fix compositor edge cases, process handing and other cool improvements

compositor/Cargo.toml

@@ -36,3 +36,5 @@ tempfile.workspace = true
 [features]
 # Opt-in counters/histograms with a per-client exit summary.
 resize-metrics = []
+# One-shot KMS recovery checks; never enabled by the installer.
+drm-fault-injection = []

compositor/src/backends/direct.rs

@@ -10,6 +10,7 @@ mod lid;
 mod mirror;
 mod output_power;
 mod planes;
+mod recovery;
 mod redraw;
 mod scheduling;
 mod topology;
@@ -260,6 +261,8 @@ struct DirectOutput {
     capture_texture: Option<GlesTexture>,
     render_metrics: RenderMetrics,
     frame_pending: bool,
+    completion: recovery::Completion,
+    completion_timer: Option<RegistrationToken>,
     animation_fallback: AnimationFallback,
     cursor_visible: bool,
     scheduler: crate::frame_scheduler::FrameScheduler,
@@ -800,23 +803,43 @@ fn open_device(state: &mut Ferese, path: &Path) -> Result<DrmNode, Box<dyn Error
         .loop_handle
         .insert_source(notifier, move |event, metadata, state| match event {
             DrmEvent::VBlank(crtc) => {
+                #[cfg(feature = "drm-fault-injection")]
+                if state
+                    .direct_backend
+                    .as_ref()
+                    .and_then(|backend| backend.devices.get(&node))
+                    .and_then(|device| device.outputs.get(&crtc))
+                    .is_some_and(|output| output.frame_pending)
+                    && recovery::inject("missing-completion")
+                {
+                    tracing::warn!(?node, ?crtc, "injecting missing DRM completion");
+                    return;
+                }
+
                 if let Some(metadata) = metadata {
                     let mut retired = false;
+                    let mut retirement_failed = false;
                     let feedback = state
                         .direct_backend
                         .as_mut()
                         .and_then(|backend| backend.devices.get_mut(&node))
                         .and_then(|device| device.outputs.get_mut(&crtc))
-                        .and_then(|output| match output.surface.frame_submitted() {
-                            Ok(feedback) => {
-                                retired = feedback.is_some();
-                                feedback
+                        .and_then(|output| {
+                            #[cfg(feature = "drm-fault-injection")]
+                            if output.frame_pending && recovery::inject("retirement") {
+                                tracing::warn!(?node, ?crtc, "injecting DRM retirement failure");
+                                retirement_failed = true;
+                                return None;
                             }
 
-                            Err(error) => {
+                            let (feedback, completed, error) = recovery::retirement(output.surface.frame_submitted());
+                            retired = completed;
+                            if let Some(error) = error {
                                 tracing::error!(?node, ?crtc, %error, "failed to retire DRM frame");
-                                None
+                                retirement_failed = true;
                             }
+
+                            feedback
                         });
 
                     if let (Some(mut feedback), DrmEventTime::Monotonic(time)) = (feedback, metadata.time) {
@@ -852,6 +875,7 @@ fn open_device(state: &mut Ferese, path: &Path) -> Result<DrmNode, Box<dyn Error
                         .and_then(|device| device.outputs.get_mut(&crtc))
                         && retired
                     {
+                        output.completion.retired();
                         output.frame_pending = false;
                         output.power.presented();
                         if let DrmEventTime::Monotonic(timestamp) = metadata.time {
@@ -886,6 +910,11 @@ fn open_device(state: &mut Ferese, path: &Path) -> Result<DrmNode, Box<dyn Error
                         state.refresh_idle_inhibition();
                     }
 
+                    if retirement_failed {
+                        recovery::reconcile_device(state, node);
+                        return;
+                    }
+
                     apply_output_power(state);
 
                     state.record_drm_presentation(node, crtc, metadata.time, metadata.sequence);
@@ -1168,6 +1197,10 @@ pub(crate) fn system_resumed(state: &mut Ferese) {
     lid::request_refresh(state, true);
 }
 
+pub(crate) fn reconcile_after_monitor_recovery(state: &mut Ferese) {
+    lid::request_reconcile(state);
+}
+
 fn internal_connector(interface: connector::Interface) -> bool {
     matches!(
         interface,
@@ -1268,19 +1301,19 @@ fn render_output(
                 primary.sync.wait()?;
             }
 
-            if output.mirror_source.is_some() {
-                capture::capture_mirror(state, &mut device.renderer, &scene_output, &frame, &mut output)?;
-            } else {
-                capture::capture_output(
-                    state,
-                    &mut device.renderer,
-                    &mut output.capture_texture,
-                    &output.output,
-                    &frame,
-                )?;
-            }
-
             if result.is_empty {
+                if output.mirror_source.is_some() {
+                    capture::capture_mirror(state, &mut device.renderer, &scene_output, &frame, &mut output);
+                } else {
+                    capture::capture_output(
+                        state,
+                        &mut device.renderer,
+                        &mut output.capture_texture,
+                        &output.output,
+                        &frame,
+                    );
+                }
+
                 output
                     .render_metrics
                     .record_no_damage(render_started.elapsed(), missed_deadlines);
@@ -1327,16 +1360,35 @@ fn render_output(
             };
             let visibility = result.states.clone();
             drop(result);
-            output.surface.queue_frame(presentation)?;
-            if output.mirror_source.is_none() {
-                state.display_presentation.queued(&output.output, &visibility);
-            }
-            output.primary_commit = primary_commit;
-            output
-                .render_metrics
-                .record_frame(render_started.elapsed(), &damage, missed_deadlines, effects);
-            output.frame_pending = true;
-            output.lock_frame_pending = state.session_lock.active();
+
+            capture::after_queue(output.surface.queue_frame(presentation), || {
+                if output.mirror_source.is_none() {
+                    state.display_presentation.queued(&output.output, &visibility);
+                }
+                output.primary_commit = primary_commit;
+                output
+                    .render_metrics
+                    .record_frame(render_started.elapsed(), &damage, missed_deadlines, effects);
+                output.frame_pending = true;
+                if !recovery::arm_completion(&state.loop_handle, node, crtc, &mut output) {
+                    recovery::reconcile_device(state, node);
+                }
+
+                output.lock_frame_pending = state.session_lock.active();
+
+                if output.mirror_source.is_some() {
+                    capture::capture_mirror(state, &mut device.renderer, &scene_output, &frame, &mut output);
+                } else {
+                    capture::capture_output(
+                        state,
+                        &mut device.renderer,
+                        &mut output.capture_texture,
+                        &output.output,
+                        &frame,
+                    );
+                }
+            })?;
+
             Ok(true)
         })()
     };
@@ -2042,6 +2094,8 @@ fn create_direct_output(
         capture_texture: None,
         render_metrics,
         frame_pending: false,
+        completion: Default::default(),
+        completion_timer: None,
         animation_fallback: AnimationFallback::default(),
         cursor_visible: false,
         power: OutputPower::default(),

compositor/src/backends/direct/capture.rs

@@ -3,6 +3,7 @@ use smithay::backend::renderer::element::RenderElement;
 use smithay::backend::renderer::gles::{GlesError, GlesRenderer, GlesTarget, GlesTexture};
 use smithay::backend::renderer::{Bind, Offscreen, Texture};
 use smithay::output::Output;
+use std::fmt::Display;
 
 use crate::Ferese;
 use crate::render::{capture_output_elements, redraw_output};
@@ -14,7 +15,7 @@ pub(crate) fn capture_output(
     texture: &mut Option<GlesTexture>,
     output: &Output,
     scene: &FrameScene,
-) -> Result<(), GlesError> {
+) {
     for include_cursor in [true, false] {
         if !state.has_pending_screencopy(output, include_cursor) {
             continue;
@@ -23,11 +24,13 @@ pub(crate) fn capture_output(
         // Sample the same scene into an independent target: the displayed
         // primary buffer may omit both a scanned-out client and hardware cursor.
         let elements = capture_output_elements(state, renderer, output, include_cursor, scene);
-        let target = render_capture(renderer, texture, output, &elements)?;
+        let Some(target) = capture_request(state, output, include_cursor, || {
+            render_capture(renderer, texture, output, &elements)
+        }) else {
+            continue;
+        };
         state.process_screencopies(renderer, &target, output, include_cursor);
     }
-
-    Ok(())
 }
 
 pub(super) fn capture_mirror(
@@ -36,7 +39,7 @@ pub(super) fn capture_mirror(
     source: &Output,
     scene: &FrameScene,
     output: &mut super::DirectOutput,
-) -> Result<(), GlesError> {
+) {
     for include_cursor in [true, false] {
         if !state.has_pending_screencopy(&output.output, include_cursor) {
             continue;
@@ -44,17 +47,46 @@ pub(super) fn capture_mirror(
         let elements = capture_output_elements(state, renderer, source, include_cursor, scene);
         // Never sample mirror_texture: it contains the unfiltered display.
         let canvas = output.mirror_canvas.as_ref().expect("mirror display composed");
-        super::mirror::compose(renderer, &mut output.mirror_capture_texture, canvas, source, &elements)?;
+        let Some(()) = capture_request(state, &output.output, include_cursor, || {
+            super::mirror::compose(renderer, &mut output.mirror_capture_texture, canvas, source, &elements)
+        }) else {
+            continue;
+        };
         let element = super::mirror::fitted_texture(
             output.mirror_capture_texture.as_ref().unwrap().clone(),
             &output.output,
             smithay::backend::renderer::element::Id::new(),
             Default::default(),
         );
-        let target = render_capture(renderer, &mut output.capture_texture, &output.output, &[element])?;
+        let Some(target) = capture_request(state, &output.output, include_cursor, || {
+            render_capture(renderer, &mut output.capture_texture, &output.output, &[element])
+        }) else {
+            continue;
+        };
         state.process_screencopies(renderer, &target, &output.output, include_cursor);
     }
-    Ok(())
+}
+
+fn capture_request<T, E: Display>(
+    state: &mut Ferese,
+    output: &Output,
+    include_cursor: bool,
+    render: impl FnOnce() -> Result<T, E>,
+) -> Option<T> {
+    match render() {
+        Ok(target) => Some(target),
+        Err(error) => {
+            tracing::warn!(?output, include_cursor, %error, "screencopy render failed");
+            state.fail_screencopies(output, include_cursor);
+            None
+        }
+    }
+}
+
+pub(super) fn after_queue<T, E>(queued: Result<T, E>, capture: impl FnOnce()) -> Result<T, E> {
+    let queued = queued?;
+    capture();
+    Ok(queued)
 }
 
 pub(super) fn render_capture<'a, E: RenderElement<GlesRenderer>>(
@@ -178,3 +210,93 @@ mod tests {
         assert_eq!(capture.as_ref().unwrap().size(), (48, 16).into());
     }
 }
+
+#[cfg(test)]
+mod failure_tests {
+    use std::cell::Cell;
+
+    use calloop::channel::channel;
+    use smithay::output::Output;
+    use smithay::utils::{Buffer, Rectangle};
+
+    use super::*;
+
+    #[test]
+    fn capture_allocation_failure_fails_one_request_after_display_submission() {
+        if !crate::startup_tests::private_runtime(
+            "backends::direct::capture::failure_tests::capture_allocation_failure_fails_one_request_after_display_submission",
+        ) {
+            return;
+        }
+
+        let mut events = calloop::EventLoop::try_new().unwrap();
+        let mut state = crate::startup_tests::state(&mut events);
+        let output = Output::new(
+            "capture-failure".into(),
+            smithay::output::PhysicalProperties {
+                size: (0, 0).into(),
+                subpixel: smithay::output::Subpixel::Unknown,
+                make: "test".into(),
+                model: "test".into(),
+            },
+        );
+        let (sender, receiver) = channel();
+        state
+            .pending_screencopies
+            .push(crate::handlers::screencopy::PendingScreencopy::owned(
+                41,
+                0,
+                sender,
+                output.clone(),
+                Rectangle::<i32, Buffer>::from_size((16, 16).into()),
+            ));
+        let other_output = Output::new(
+            "other-capture".into(),
+            smithay::output::PhysicalProperties {
+                size: (0, 0).into(),
+                subpixel: smithay::output::Subpixel::Unknown,
+                make: "test".into(),
+                model: "test".into(),
+            },
+        );
+        let (other_sender, other_receiver) = channel();
+        state
+            .pending_screencopies
+            .push(crate::handlers::screencopy::PendingScreencopy::owned(
+                42,
+                0,
+                other_sender,
+                other_output.clone(),
+                Rectangle::<i32, Buffer>::from_size((16, 16).into()),
+            ));
+
+        let submitted = Cell::new(false);
+        let queued = {
+            submitted.set(true);
+            Ok::<(), ()>(())
+        };
+        after_queue(queued, || {
+            assert!(submitted.get(), "capture must run after the display queue succeeds");
+            assert!(
+                capture_request(&mut state, &output, false, || Err::<(), _>(
+                    "injected allocation failure"
+                ))
+                .is_none()
+            );
+        })
+        .unwrap();
+
+        assert!(submitted.get(), "capture failure must not undo queued display work");
+        assert_eq!(state.pending_screencopies.len(), 1);
+        assert_eq!(state.pending_screencopies[0].output, other_output);
+        let outcome = receiver.try_recv().unwrap();
+        assert_eq!(outcome.request, 41);
+        assert_eq!(outcome.part, 0);
+        assert!(outcome.result.is_err());
+        assert!(receiver.try_recv().is_err(), "request should fail exactly once");
+        assert!(
+            other_receiver.try_recv().is_err(),
+            "other output's request must stay pending"
+        );
+    }
+}

compositor/src/backends/direct/lid.rs

@@ -8,6 +8,7 @@ pub(super) struct Probe {
     serial: u64,
     revision: u64,
     reactivate: bool,
+    wake: bool,
 }
 
 #[derive(Default)]
@@ -33,12 +34,13 @@ impl LidState {
         changed
     }
 
-    fn begin(&mut self, reactivate: bool) -> Probe {
+    fn begin(&mut self, reactivate: bool, wake: bool) -> Probe {
         self.serial = self.serial.wrapping_add(1);
         let probe = Probe {
             serial: self.serial,
             revision: self.revision,
             reactivate: reactivate || self.pending.is_some_and(|pending| pending.reactivate),
+            wake: wake || self.pending.is_some_and(|pending| pending.wake),
         };
         self.pending = Some(probe);
         probe
@@ -269,6 +271,15 @@ impl Reader {
 }
 
 pub(super) fn request_refresh(state: &mut Ferese, reactivate: bool) {
+    request(state, reactivate, true);
+}
+
+/// Listener recovery reconciles hardware without resetting idle activity.
+pub(super) fn request_reconcile(state: &mut Ferese) {
+    request(state, false, false);
+}
+
+fn request(state: &mut Ferese, reactivate: bool, wake: bool) {
     let Some(backend) = state.direct_backend.as_mut() else {
         return;
     };
@@ -289,7 +300,7 @@ pub(super) fn request_refresh(state: &mut Ferese, reactivate: bool) {
     }
     backend.lid_reader.suspend_requested = false;
     backend.lid_reader.lease.lock().unwrap().suspend = false;
-    let probe = backend.lid.begin(reactivate);
+    let probe = backend.lid.begin(reactivate, wake);
     let sent = backend.lid_reader.requests.send(probe).is_ok();
     let timer = state
         .loop_handle
@@ -329,10 +340,13 @@ fn complete_refresh(state: &mut Ferese, probe: Probe, value: Option<bool>) {
     // Waking a locked session may request redraws. Hold them until the fresh
     // device/connector snapshot has been reconciled.
     backend.lid_reader.suspend_requested = false;
-    backend.topology.reconciling = true;
-    state.reset_animation_clock();
-    state.lock_input_activity();
-    state.direct_backend.as_mut().unwrap().topology.reconciling = false;
+    if probe.wake {
+        backend.topology.reconciling = true;
+        state.reset_animation_clock();
+        state.lock_input_activity();
+        state.direct_backend.as_mut().unwrap().topology.reconciling = false;
+    }
+
     reconcile_outputs(state, reactivate);
 }
 
@@ -431,7 +445,7 @@ mod tests {
     fn newer_input_wins_over_a_delayed_resume_read() {
         let mut lid = LidState::default();
         lid.observe(true);
-        let probe = lid.begin(true);
+        let probe = lid.begin(true, true);
         lid.observe(false);
         assert_eq!(lid.complete(probe, Some(true)), Some(true));
         assert!(!lid.closed());
@@ -440,11 +454,11 @@ mod tests {
     #[test]
     fn failed_reads_preserve_known_state_and_unknown_is_not_an_open_observation() {
         let mut lid = LidState::default();
-        let probe = lid.begin(false);
+        let probe = lid.begin(false, true);
         lid.complete(probe, None);
         assert_eq!(lid.value, None);
         lid.observe(true);
-        let probe = lid.begin(true);
+        let probe = lid.begin(true, true);
         lid.complete(probe, None);
         assert_eq!(lid.value, Some(true));
     }
@@ -452,21 +466,39 @@ mod tests {
     #[test]
     fn pause_and_newer_resume_invalidate_old_replies() {
         let mut lid = LidState::default();
-        let old = lid.begin(true);
+        let old = lid.begin(true, true);
         lid.pause();
         assert_eq!(lid.complete(old, Some(true)), None);
-        let current = lid.begin(true);
+        let current = lid.begin(true, true);
         assert_eq!(lid.complete(old, Some(true)), None);
         assert!(lid.pending());
         assert_eq!(lid.complete(current, Some(false)), Some(true));
         assert!(!lid.pending());
     }
 
+    #[test]
+    fn listener_recovery_does_not_request_idle_wake_or_reactivation() {
+        let mut lid = LidState::default();
+        let recovery = lid.begin(false, false);
+        assert!(!recovery.wake);
+        assert_eq!(lid.complete(recovery, Some(false)), Some(false));
+    }
+
+    #[test]
+    fn listener_recovery_preserves_a_pending_real_wake() {
+        let mut lid = LidState::default();
+        let resume = lid.begin(true, true);
+        let recovery = lid.begin(false, false);
+        assert!(recovery.wake);
+        assert_eq!(lid.complete(resume, Some(false)), None);
+        assert_eq!(lid.complete(recovery, Some(false)), Some(true));
+    }
+
     #[test]
     fn system_wake_cannot_cancel_pending_session_reactivation() {
         let mut lid = LidState::default();
-        lid.begin(true);
-        let probe = lid.begin(false);
+        lid.begin(true, true);
+        let probe = lid.begin(false, true);
         assert_eq!(lid.complete(probe, Some(false)), Some(true));
     }
 }

compositor/src/backends/direct/recovery.rs

@@ -0,0 +1,165 @@
+//! Uncertain KMS completion requires device reconciliation, not buffer reuse.
+use super::*;
+
+const COMPLETION_TIMEOUT: Duration = Duration::from_secs(2);
+
+#[cfg(feature = "drm-fault-injection")]
+pub(super) fn inject(mode: &str) -> bool {
+    use std::sync::LazyLock;
+    use std::sync::atomic::{AtomicBool, Ordering};
+
+    static MODE: LazyLock<Option<String>> = LazyLock::new(|| std::env::var("FERESE_TEST_DRM_FAILURE").ok());
+    static USED: AtomicBool = AtomicBool::new(false);
+    MODE.as_deref() == Some(mode) && !USED.swap(true, Ordering::AcqRel)
+}
+
+#[derive(Default)]
+pub(super) struct Completion {
+    pending: Option<Instant>,
+}
+
+impl Completion {
+    fn queued(&mut self, now: Instant) {
+        self.pending = Some(now);
+    }
+
+    pub fn retired(&mut self) {
+        self.pending = None;
+    }
+
+    fn remaining(&self, now: Instant) -> Option<Duration> {
+        self.pending
+            .map(|queued| COMPLETION_TIMEOUT.saturating_sub(now.saturating_duration_since(queued)))
+    }
+}
+
+// Keep the submission result and the recovery decision together. An error must
+// not be mistaken for a completed frame with no presentation feedback.
+pub(super) fn retirement<T, E>(result: Result<Option<T>, E>) -> (Option<T>, bool, Option<E>) {
+    match result {
+        Ok(feedback) => {
+            let retired = feedback.is_some();
+            (feedback, retired, None)
+        }
+        Err(error) => (None, false, Some(error)),
+    }
+}
+
+pub(super) fn arm_completion(
+    handle: &smithay::reexports::calloop::LoopHandle<'static, Ferese>,
+    node: DrmNode,
+    crtc: crtc::Handle,
+    output: &mut DirectOutput,
+) -> bool {
+    output.completion.queued(Instant::now());
+    if output.completion_timer.is_some() {
+        return true;
+    }
+
+    let identity = output.output.clone();
+    match handle.insert_source(Timer::from_duration(COMPLETION_TIMEOUT), move |_, _, state| {
+        let Some(output) = state
+            .direct_backend
+            .as_mut()
+            .and_then(|backend| backend.devices.get_mut(&node))
+            .and_then(|device| device.outputs.get_mut(&crtc))
+            .filter(|output| output.output == identity)
+        else {
+            return TimeoutAction::Drop;
+        };
+
+        if let Some(remaining) = output.completion.remaining(Instant::now()) {
+            if !remaining.is_zero() {
+                return TimeoutAction::ToDuration(remaining);
+            }
+
+            output.completion_timer = None;
+            tracing::error!(?node, ?crtc, "DRM frame completion timed out; reconciling device");
+            reconcile_device(state, node);
+        } else {
+            output.completion_timer = None;
+        }
+
+        TimeoutAction::Drop
+    }) {
+        Ok(token) => {
+            output.completion_timer = Some(token);
+            true
+        }
+        Err(error) => {
+            tracing::error!(%error, ?node, ?crtc, "could not arm DRM completion watchdog");
+            false
+        }
+    }
+}
+
+pub(super) fn reconcile_device(state: &mut Ferese, node: DrmNode) {
+    let Some(backend) = state.direct_backend.as_mut() else {
+        return;
+    };
+    backend.topology.dirty = true;
+    if !backend.topology.invalidated.insert(node) {
+        return;
+    }
+
+    // Defer teardown until the DRM notifier callback has returned. Inactive
+    // sessions retain the invalidation for fresh enumeration on activation.
+    let active = backend.active;
+    if active {
+        match state.loop_handle.insert_source(Timer::immediate(), |_, _, state| {
+            reconcile_outputs(state, false);
+            TimeoutAction::Drop
+        }) {
+            Ok(_) => (),
+            Err(error) => tracing::error!(%error, "could not schedule DRM device recovery"),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn failed_retirement_does_not_release_pending_buffer_ownership() {
+        let now = Instant::now();
+        let mut completion = Completion::default();
+        completion.queued(now);
+        let (feedback, retired, error) = retirement::<(), _>(Err("injected KMS retirement failure"));
+        assert_eq!(feedback, None);
+        assert!(!retired);
+        assert!(error.is_some(), "the production handler must reconcile the device");
+        assert_eq!(completion.remaining(now), Some(COMPLETION_TIMEOUT));
+        assert_eq!(retirement::<(), &str>(Ok(None)), (None, false, None));
+        assert_eq!(retirement::<(), &str>(Ok(Some(()))), (Some(()), true, None));
+
+        // Only successful retirement or device teardown can end uncertainty.
+        completion = Completion::default();
+        assert_eq!(completion.remaining(now), None);
+    }
+
+    #[test]
+    fn missing_completion_remains_pending_until_hardware_reconciliation() {
+        let now = Instant::now();
+        let mut completion = Completion::default();
+        completion.queued(now);
+        assert_eq!(
+            completion.remaining(now + COMPLETION_TIMEOUT - Duration::from_millis(1)),
+            Some(Duration::from_millis(1))
+        );
+        // A timeout observes uncertainty; it never frees the current buffer.
+        assert_eq!(completion.remaining(now + COMPLETION_TIMEOUT), Some(Duration::ZERO));
+        assert_eq!(
+            completion.remaining(now + COMPLETION_TIMEOUT + Duration::from_secs(1)),
+            Some(Duration::ZERO)
+        );
+        completion.retired();
+        assert_eq!(completion.remaining(now), None);
+        completion.queued(now + Duration::from_secs(3));
+        assert_eq!(
+            completion.remaining(now + Duration::from_secs(4)),
+            Some(Duration::from_secs(1)),
+            "existing timer must respect the newer frame's deadline"
+        );
+    }
+}

compositor/src/backends/direct/scheduling.rs

@@ -9,9 +9,14 @@ pub(super) fn cancel_output_timers(
     handle: &smithay::reexports::calloop::LoopHandle<'static, Ferese>,
     output: &mut DirectOutput,
 ) {
-    for token in [output.render_timer.take(), output.callback_timer.take()]
-        .into_iter()
-        .flatten()
+    output.completion.retired();
+    for token in [
+        output.render_timer.take(),
+        output.callback_timer.take(),
+        output.completion_timer.take(),
+    ]
+    .into_iter()
+    .flatten()
     {
         handle.remove(token);
     }

compositor/src/daemon.rs

@@ -1,7 +1,6 @@
 //! Session-owned services. Never grant shell/effects privileges to daemons.
 use std::cell::RefCell;
 use std::collections::HashMap;
-use std::os::fd::{FromRawFd, OwnedFd};
 use std::process::Child;
 use std::rc::Rc;
 use std::time::{Duration, Instant};
@@ -13,6 +12,7 @@ use smithay::reexports::calloop::{Interest, Mode, PostAction, RegistrationToken}
 use crate::Ferese;
 use crate::config::DaemonConfig;
 use crate::private_client::ClientCapabilities;
+use crate::process::{pidfd, spawn_client, terminate_child};
 
 struct Service {
     config: DaemonConfig,
@@ -27,16 +27,6 @@ pub(crate) struct Runner(
     Option<(RegistrationToken, Instant)>,
 );
 
-fn pidfd(pid: u32) -> std::io::Result<OwnedFd> {
-    // SAFETY: pidfd_open has no pointer arguments and returns a new owned fd.
-    let fd = unsafe { libc::syscall(libc::SYS_pidfd_open, pid, 0) };
-    if fd < 0 {
-        return Err(std::io::Error::last_os_error());
-    }
-    // SAFETY: a successful syscall returned a unique valid descriptor.
-    Ok(unsafe { OwnedFd::from_raw_fd(fd as i32) })
-}
-
 impl Runner {
     pub fn start(state: &mut Ferese) -> Rc<RefCell<Self>> {
         let runner = Rc::new(RefCell::new(Self::new(
@@ -153,7 +143,7 @@ impl Runner {
         // TERM/grace/reaping must not pause the compositor's event loop.
         for mut removed in previous {
             if let Some(mut child) = removed.child.take() {
-                std::thread::spawn(move || crate::terminate_child(&mut child));
+                std::thread::spawn(move || terminate_child(&mut child));
             }
         }
     }
@@ -195,11 +185,7 @@ impl Runner {
                 }
             }
             if !service.finished && now >= service.next_start {
-                service.child = crate::spawn_client(
-                    state,
-                    service.config.command.iter().map(Into::into).collect(),
-                    ClientCapabilities::default(),
-                );
+                service.child = spawn_client(state, service.config.command.iter(), ClientCapabilities::default());
                 service.next_start = now + Duration::from_secs(5);
                 if service.child.is_none() && !service.config.restart {
                     service.finished = true;
@@ -211,7 +197,7 @@ impl Runner {
     pub fn stop(&mut self) {
         for service in &mut self.0 {
             if let Some(mut child) = service.child.take() {
-                crate::terminate_child(&mut child);
+                terminate_child(&mut child);
             }
             service.finished = true;
         }

compositor/src/grabs/mod.rs

@@ -2,4 +2,4 @@ mod move_grab;
 mod resize_grab;
 
 pub use move_grab::MoveSurfaceGrab;
-pub use resize_grab::{ResizeEdge, ResizeSurfaceGrab, handle_resize_commit};
+pub use resize_grab::{ResizeEdge, ResizeSurfaceGrab};

compositor/src/grabs/resize_grab.rs

@@ -1,5 +1,3 @@
-use std::cell::RefCell;
-
 use smithay::desktop::Window;
 use smithay::input::pointer::{
     AxisFrame, ButtonEvent, GestureHoldBeginEvent, GestureHoldEndEvent, GesturePinchBeginEvent, GesturePinchEndEvent,
@@ -98,10 +96,6 @@ impl ResizeSurfaceGrab {
         edges: ResizeEdge,
         initial_rect: Rectangle<i32, Logical>,
     ) -> Self {
-        ResizeState::with(
-            window.toplevel().expect("managed window has a toplevel").wl_surface(),
-            |state| *state = ResizeState::Resizing { edges, initial_rect },
-        );
         Self {
             start_data,
             window,
@@ -128,8 +122,8 @@ impl PointerGrab<Ferese> for ResizeSurfaceGrab {
         let initial = self.initial_rect;
         let raw_left = initial.loc.x as f64 + if self.edges.left() { delta.x } else { 0. };
         let raw_top = initial.loc.y as f64 + if self.edges.top() { delta.y } else { 0. };
-        let raw_right = (initial.loc.x + initial.size.w) as f64 + if self.edges.right() { delta.x } else { 0. };
-        let raw_bottom = (initial.loc.y + initial.size.h) as f64 + if self.edges.bottom() { delta.y } else { 0. };
+        let raw_right = initial.loc.x as f64 + initial.size.w as f64 + if self.edges.right() { delta.x } else { 0. };
+        let raw_bottom = initial.loc.y as f64 + initial.size.h as f64 + if self.edges.bottom() { delta.y } else { 0. };
         let raw = ferese_layout::Rect::new(
             raw_left,
             raw_top,
@@ -203,12 +197,6 @@ impl PointerGrab<Ferese> for ResizeSurfaceGrab {
                 state.size = Some(self.last_size);
             });
             surface.send_pending_configure();
-            ResizeState::with(surface.wl_surface(), |state| {
-                *state = ResizeState::WaitingForFinalCommit {
-                    edges: self.edges,
-                    initial_rect: self.initial_rect,
-                };
-            });
         }
     }
 
@@ -307,57 +295,10 @@ impl PointerGrab<Ferese> for ResizeSurfaceGrab {
             state.size = Some(self.initial_rect.size);
         });
         surface.send_pending_configure();
-        ResizeState::with(surface.wl_surface(), |state| *state = ResizeState::Idle);
         data.set_floating_window_geometry(&self.window, self.initial_rect.loc, self.initial_rect.size);
     }
 }
 
-#[derive(Clone, Copy, Debug, Default)]
-enum ResizeState {
-    #[default]
-    Idle,
-    Resizing {
-        edges: ResizeEdge,
-        initial_rect: Rectangle<i32, Logical>,
-    },
-    WaitingForFinalCommit {
-        edges: ResizeEdge,
-        initial_rect: Rectangle<i32, Logical>,
-    },
-}
-
-impl ResizeState {
-    fn with<T>(surface: &WlSurface, callback: impl FnOnce(&mut Self) -> T) -> T {
-        with_states(surface, |states| {
-            states.data_map.insert_if_missing(RefCell::<Self>::default);
-            callback(
-                &mut states
-                    .data_map
-                    .get::<RefCell<Self>>()
-                    .expect("resize state was inserted")
-                    .borrow_mut(),
-            )
-        })
-    }
-
-    fn commit(&mut self) -> Option<(ResizeEdge, Rectangle<i32, Logical>)> {
-        match *self {
-            Self::Idle => None,
-            Self::Resizing { edges, initial_rect } => Some((edges, initial_rect)),
-            Self::WaitingForFinalCommit { edges, initial_rect } => {
-                *self = Self::Idle;
-                Some((edges, initial_rect))
-            }
-        }
-    }
-}
-
-pub fn handle_resize_commit(surface: &WlSurface) {
-    // The compositor's visual rect owns the anchored edge. A delayed client
-    // commit must not move the window or change its stacking order.
-    ResizeState::with(surface, ResizeState::commit);
-}
-
 fn constrained_size(
     initial: Size<i32, Logical>,
     delta: Point<f64, Logical>,
@@ -368,21 +309,34 @@ fn constrained_size(
     let mut width = initial.w;
     let mut height = initial.h;
     if edges.left() {
-        width -= delta.x as i32;
+        width = width.saturating_sub(delta.x as i32);
     } else if edges.right() {
-        width += delta.x as i32;
-    }
-    if edges.top() {
-        height -= delta.y as i32;
-    } else if edges.bottom() {
-        height += delta.y as i32;
+        width = width.saturating_add(delta.x as i32);
     }
 
-    let maximum_width = if maximum.w == 0 { i32::MAX } else { maximum.w };
-    let maximum_height = if maximum.h == 0 { i32::MAX } else { maximum.h };
+    if edges.top() {
+        height = height.saturating_sub(delta.y as i32);
+    } else if edges.bottom() {
+        height = height.saturating_add(delta.y as i32);
+    }
+
+    // Protocol validation rejects these ranges, but a grab may still be alive
+    // when its client is disconnected. Keep this path safe for any cached state.
+    let minimum_width = minimum.w.max(1);
+    let minimum_height = minimum.h.max(1);
+    let maximum_width = if maximum.w <= 0 {
+        i32::MAX
+    } else {
+        maximum.w.max(minimum_width)
+    };
+    let maximum_height = if maximum.h <= 0 {
+        i32::MAX
+    } else {
+        maximum.h.max(minimum_height)
+    };
     (
-        width.clamp(minimum.w.max(1), maximum_width),
-        height.clamp(minimum.h.max(1), maximum_height),
+        width.clamp(minimum_width, maximum_width),
+        height.clamp(minimum_height, maximum_height),
     )
         .into()
 }
@@ -395,10 +349,11 @@ fn resized_rect(
     let mut location = initial.loc;
 
     if edges.left() {
-        location.x += initial.size.w - size.w;
+        location.x = location.x.saturating_add(initial.size.w.saturating_sub(size.w));
     }
+
     if edges.top() {
-        location.y += initial.size.h - size.h;
+        location.y = location.y.saturating_add(initial.size.h.saturating_sub(size.h));
     }
 
     Rectangle::new(location, size)
@@ -469,6 +424,32 @@ mod tests {
         assert_eq!(size, (1_024, 768).into());
     }
 
+    #[test]
+    fn invalid_and_extreme_client_limits_cannot_panic_or_overflow() {
+        for (minimum, maximum) in [
+            ((800, 700), (400, 300)),
+            ((-1, -2), (-3, -4)),
+            ((i32::MAX, i32::MAX), (1, 1)),
+            ((0, 0), (0, 0)),
+        ] {
+            for delta in [(f64::MAX, f64::MAX), (-f64::MAX, -f64::MAX), (0.0, 0.0)] {
+                let size = constrained_size(
+                    (800, 600).into(),
+                    delta.into(),
+                    ResizeEdge(xdg_toplevel::ResizeEdge::BottomRight),
+                    minimum.into(),
+                    maximum.into(),
+                );
+                assert!(size.w >= 1 && size.h >= 1);
+                let _ = resized_rect(
+                    Rectangle::new((100, 80).into(), (800, 600).into()),
+                    size,
+                    ResizeEdge(xdg_toplevel::ResizeEdge::TopLeft),
+                );
+            }
+        }
+    }
+
     #[test]
     fn resized_rect_keeps_the_opposite_edge_fixed() {
         let initial = Rectangle::new((100, 80).into(), (800, 600).into());

compositor/src/handlers/activation.rs

@@ -1,4 +1,9 @@
-use std::time::Duration;
+use std::collections::VecDeque;
+use std::time::{Duration, Instant};
+
+use smithay::input::Seat;
+use smithay::reexports::wayland_server::{Resource, backend::ClientId};
+use smithay::utils::Serial;
 
 use smithay::reexports::wayland_server::protocol::wl_surface::WlSurface;
 use smithay::utils::SERIAL_COUNTER;
@@ -9,6 +14,50 @@ use smithay::wayland::xdg_activation::{
 use crate::Ferese;
 
 const TOKEN_MAX_AGE: Duration = Duration::from_secs(10);
+const MAX_INTERACTIONS: usize = 64;
+
+pub(crate) struct InputHistory<C = ClientId> {
+    events: VecDeque<(Serial, C, Instant)>,
+}
+
+impl<C> Default for InputHistory<C> {
+    fn default() -> Self {
+        Self {
+            events: VecDeque::new(),
+        }
+    }
+}
+
+impl<C: PartialEq> InputHistory<C> {
+    fn record(&mut self, serial: Serial, client: C, time: Instant) {
+        while self.events.len() >= MAX_INTERACTIONS {
+            self.events.pop_front();
+        }
+
+        self.events.push_back((serial, client, time));
+    }
+
+    fn validate(&self, serial: Serial, client: &C, now: Instant) -> Option<Instant> {
+        self.events.iter().rev().find_map(|(event, owner, time)| {
+            (*event == serial && owner == client && now.saturating_duration_since(*time) <= TOKEN_MAX_AGE)
+                .then_some(*time)
+        })
+    }
+}
+
+struct ApprovedInteraction(Instant);
+
+impl Ferese {
+    pub(crate) fn record_activation_input(&mut self, serial: Serial, surface: Option<WlSurface>) {
+        if self.session_lock.active() || self.input_capture.active() {
+            return;
+        }
+
+        if let Some(client) = surface.and_then(|surface| surface.client()) {
+            self.activation_inputs.record(serial, client.id(), Instant::now());
+        }
+    }
+}
 
 impl XdgActivationHandler for Ferese {
     fn activation_state(&mut self) -> &mut XdgActivationState {
@@ -16,15 +65,46 @@ impl XdgActivationHandler for Ferese {
     }
 
     fn token_created(&mut self, _token: XdgActivationToken, data: XdgActivationTokenData) -> bool {
-        data.serial.is_some() && data.timestamp.elapsed() <= TOKEN_MAX_AGE
+        if self.session_lock.active() || self.input_capture.active() {
+            return false;
+        }
+
+        let Some((serial, seat)) = &data.serial else {
+            return false;
+        };
+        let Some(client) = &data.client_id else {
+            return false;
+        };
+        if Seat::<Self>::from_resource(seat).as_ref() != Some(&self.seat)
+            || seat.client().is_none_or(|owner| owner.id() != *client)
+            || data
+                .surface
+                .as_ref()
+                .is_some_and(|surface| surface.client().is_none_or(|owner| owner.id() != *client))
+        {
+            return false;
+        }
+
+        let Some(time) = self.activation_inputs.validate(*serial, client, Instant::now()) else {
+            return false;
+        };
+        data.user_data.insert_if_missing(|| ApprovedInteraction(time));
+        true
     }
 
     fn request_activation(&mut self, token: XdgActivationToken, data: XdgActivationTokenData, surface: WlSurface) {
+        self.xdg_activation_state.remove_token(&token);
         if self.session_lock.active() || self.input_capture.captures(1) {
             return;
         }
-        let valid = data.serial.is_some() && data.timestamp.elapsed() <= TOKEN_MAX_AGE;
-        self.xdg_activation_state.remove_token(&token);
+
+        // The recipient may be a different client: launcher-to-app token handoff.
+        // Retain the original interaction time rather than renewing it at commit.
+        let valid = data.timestamp.elapsed() <= TOKEN_MAX_AGE
+            && data
+                .user_data
+                .get::<ApprovedInteraction>()
+                .is_some_and(|proof| proof.0.elapsed() <= TOKEN_MAX_AGE);
         if !valid {
             tracing::debug!("ignored stale or non-interactive activation request");
             return;
@@ -60,3 +140,163 @@ impl XdgActivationHandler for Ferese {
         });
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn token_creation_validates_real_seat_owner_and_input_age() {
+        use smithay::reexports::calloop::EventLoop;
+        use smithay::reexports::wayland_server::protocol::wl_seat::WlSeat;
+        use std::io::{Read, Write};
+        use std::os::unix::net::UnixStream;
+        use std::sync::Arc;
+
+        if !crate::startup_tests::private_runtime(
+            "handlers::activation::tests::token_creation_validates_real_seat_owner_and_input_age",
+        ) {
+            return;
+        }
+
+        let mut events = EventLoop::try_new().unwrap();
+        let mut state = crate::startup_tests::state(&mut events);
+        let (server, mut wire) = UnixStream::pair().unwrap();
+        let launcher = state
+            .display_handle
+            .insert_client(server, Arc::new(crate::state::ClientState::default()))
+            .unwrap();
+        let send = |wire: &mut UnixStream, object: u32, opcode: u32, args: &[u32]| {
+            let bytes: Vec<_> = [object, ((args.len() as u32 + 2) * 4) << 16 | opcode]
+                .into_iter()
+                .chain(args.iter().copied())
+                .flat_map(u32::to_ne_bytes)
+                .collect();
+            wire.write_all(&bytes).unwrap();
+        };
+        send(&mut wire, 1, 1, &[2]); // wl_display.get_registry
+        events.dispatch(Duration::from_millis(1), &mut state).unwrap();
+        state.display_handle.flush_clients().unwrap();
+        wire.set_nonblocking(true).unwrap();
+        let mut globals = Vec::new();
+        let _ = wire.read_to_end(&mut globals);
+        wire.set_nonblocking(false).unwrap();
+        let mut offset = 0;
+        let mut seat_name = None;
+        while offset < globals.len() {
+            let header = u32::from_ne_bytes(globals[offset + 4..offset + 8].try_into().unwrap());
+            if u32::from_ne_bytes(globals[offset..offset + 4].try_into().unwrap()) == 2 && header & 0xffff == 0 {
+                let length = u32::from_ne_bytes(globals[offset + 12..offset + 16].try_into().unwrap()) as usize;
+                if &globals[offset + 16..offset + 16 + length] == b"wl_seat\0" {
+                    seat_name = Some(u32::from_ne_bytes(globals[offset + 8..offset + 12].try_into().unwrap()));
+                }
+            }
+
+            offset += (header >> 16) as usize;
+        }
+
+        let mut args = vec![seat_name.expect("seat global"), 8];
+        args.extend(
+            b"wl_seat\0"
+                .chunks_exact(4)
+                .map(|word| u32::from_ne_bytes(word.try_into().unwrap())),
+        );
+        args.extend([7, 3]);
+        send(&mut wire, 2, 0, &args);
+        events.dispatch(Duration::from_millis(1), &mut state).unwrap();
+        let seat: WlSeat = state
+            .seat
+            .client_seats(&launcher)
+            .into_iter()
+            .next()
+            .expect("bound seat");
+        let (token, _) = state.xdg_activation_state.create_external_token(None);
+        let token = token.clone();
+        let serial = SERIAL_COUNTER.next_serial();
+        let data = || XdgActivationTokenData {
+            client_id: Some(launcher.id()),
+            serial: Some((serial, seat.clone())),
+            ..Default::default()
+        };
+        assert!(
+            !state.token_created(token.clone(), data()),
+            "fabricated serial accepted"
+        );
+        state.activation_inputs.record(
+            serial,
+            launcher.id(),
+            Instant::now() - TOKEN_MAX_AGE - Duration::from_millis(1),
+        );
+        assert!(
+            !state.token_created(token.clone(), data()),
+            "fresh token renewed stale input"
+        );
+        state.activation_inputs.record(serial, launcher.id(), Instant::now());
+        let approved = data();
+        assert!(state.token_created(token.clone(), approved.clone()));
+        assert!(approved.user_data.get::<ApprovedInteraction>().is_some());
+
+        let (server, mut recipient_wire) = UnixStream::pair().unwrap();
+        let recipient = state
+            .display_handle
+            .insert_client(server, Arc::new(crate::state::ClientState::default()))
+            .unwrap();
+        let mut stolen = data();
+        stolen.client_id = Some(recipient.id());
+        assert!(
+            !state.token_created(token.clone(), stolen),
+            "other client claimed launcher's seat/input"
+        );
+        // The proof is attached to the token, not the recipient identity. This
+        // is what lets a validated launcher hand it to a different application.
+        assert_ne!(approved.client_id, Some(recipient.id()));
+        assert!(approved.user_data.get::<ApprovedInteraction>().unwrap().0.elapsed() < TOKEN_MAX_AGE);
+
+        // Exercise the production handler with a real recipient toplevel.
+        // Creating the window needs no GPU or client buffer.
+        use smithay::reexports::wayland_protocols::xdg::shell::server::xdg_wm_base::XdgWmBase;
+        use smithay::reexports::wayland_server::protocol::wl_compositor::WlCompositor;
+        use smithay::wayland::shell::xdg::XdgWmBaseUserData;
+        let compositor = recipient
+            .create_resource::<WlCompositor, (), Ferese>(&state.display_handle, 6, ())
+            .unwrap();
+        let shell = recipient
+            .create_resource::<XdgWmBase, XdgWmBaseUserData, Ferese>(&state.display_handle, 6, Default::default())
+            .unwrap();
+        send(&mut recipient_wire, compositor.id().protocol_id(), 0, &[2]);
+        send(&mut recipient_wire, shell.id().protocol_id(), 2, &[3, 2]);
+        send(&mut recipient_wire, 3, 1, &[4]);
+        events.dispatch(Duration::from_millis(1), &mut state).unwrap();
+        let target = state
+            .space
+            .elements()
+            .find_map(|window| {
+                let surface = window.toplevel()?.wl_surface();
+                surface
+                    .client()
+                    .is_some_and(|client| client.id() == recipient.id())
+                    .then(|| surface.clone())
+            })
+            .expect("recipient's toplevel");
+        state.request_activation(token, approved, target.clone());
+        assert_eq!(state.seat.get_keyboard().unwrap().current_focus(), Some(target));
+    }
+
+    #[test]
+    fn validates_owner_serial_and_original_interaction_age() {
+        let now = Instant::now();
+        let mut history = InputHistory::default();
+        let serial = Serial::from(12);
+        history.record(serial, "launcher", now);
+        assert_eq!(history.validate(serial, &"launcher", now), Some(now));
+        assert_eq!(history.validate(Serial::from(13), &"launcher", now), None);
+        assert_eq!(history.validate(serial, &"other-client", now), None);
+        assert_eq!(
+            history.validate(serial, &"launcher", now + TOKEN_MAX_AGE + Duration::from_millis(1)),
+            None
+        );
+        // An approved token retains the interaction time across client handoff.
+        let approved = ApprovedInteraction(history.validate(serial, &"launcher", now).unwrap());
+        assert_eq!(approved.0, now);
+    }
+}

compositor/src/handlers/compositor.rs

@@ -5,7 +5,7 @@ use smithay::reexports::wayland_server::protocol::wl_buffer;
 use smithay::reexports::wayland_server::protocol::wl_surface::WlSurface;
 use smithay::wayland::buffer::BufferHandler;
 use smithay::wayland::compositor::{
-    CompositorClientState, CompositorHandler, CompositorState, get_parent, is_sync_subsurface,
+    CompositorClientState, CompositorHandler, CompositorState, get_parent, get_role, is_sync_subsurface,
 };
 use smithay::wayland::dmabuf::{DmabufGlobal, DmabufHandler, DmabufState, ImportNotifier};
 use smithay::wayland::shm::{ShmHandler, ShmState};
@@ -35,6 +35,14 @@ impl CompositorHandler for Ferese {
     }
 
     fn commit(&mut self, surface: &WlSurface) {
+        if get_role(surface) == Some(smithay::wayland::shell::xdg::XDG_TOPLEVEL_ROLE)
+            && let Some(window) = self.window_for_surface(surface)
+            && let Some(toplevel) = window.toplevel()
+            && !xdg_shell::validate_size_constraints(toplevel)
+        {
+            return;
+        }
+
         self.update_surface_preferences(surface);
         self.capture_resize_before_commit(surface);
         self.capture_close_before_commit(surface);
@@ -45,12 +53,7 @@ impl CompositorHandler for Ferese {
             while let Some(parent) = get_parent(&root) {
                 root = parent;
             }
-            let window = {
-                self.space
-                    .elements()
-                    .find(|window| window.toplevel().is_some_and(|toplevel| toplevel.wl_surface() == &root))
-                    .cloned()
-            };
+            let window = self.window_for_surface(&root);
 
             if let Some(window) = window {
                 window.on_commit();
@@ -76,7 +79,7 @@ impl CompositorHandler for Ferese {
         self.refresh_idle_inhibition();
 
         layer_shell::handle_commit(self, surface);
-        xdg_shell::handle_commit(&mut self.popups, &mut self.space, surface);
+        xdg_shell::handle_commit(self, surface);
         crate::backends::direct::render_surface(self, surface);
     }
 

compositor/src/handlers/mod.rs

@@ -1,4 +1,4 @@
-mod activation;
+pub(crate) mod activation;
 mod compositor;
 mod input_method;
 mod layer_shell;
@@ -60,6 +60,12 @@ impl SeatHandler for Ferese {
     }
 
     fn focus_changed(&mut self, seat: &Seat<Self>, focused: Option<&WlSurface>) {
+        // Smithay has already sent enter. last_enter uses a separate mutex;
+        // querying current_focus here would reenter the held keyboard lock.
+        if let Some(serial) = seat.get_keyboard().and_then(|keyboard| keyboard.last_enter()) {
+            self.record_activation_input(serial, focused.cloned());
+        }
+
         if let Some(id) = focused.and_then(|surface| self.windows.id_for_surface(surface)) {
             self.focus_history.record(id);
         }

compositor/src/handlers/screencopy.rs

@@ -49,6 +49,7 @@ pub(crate) enum CaptureSink {
         part: usize,
         complete: PartSender,
         published: AtomicBool,
+        permit: Option<super::screenshot::BudgetPermit>,
     },
 }
 
@@ -59,6 +60,7 @@ impl CaptureSink {
             part,
             complete,
             published: AtomicBool::new(false),
+            permit: None,
         }
     }
 
@@ -73,12 +75,14 @@ impl CaptureSink {
                 part,
                 complete,
                 published,
+                permit,
             } => {
                 if !published.swap(true, Ordering::AcqRel) {
                     let _ = complete.send(PartOutcome {
                         request: *request,
                         part: *part,
                         result: Err("Screenshot part failed".to_string()),
+                        permit: permit.clone(),
                     });
                 }
             }
@@ -93,6 +97,7 @@ impl CaptureSink {
             part,
             complete,
             published,
+            permit,
         } = self
         else {
             return false;
@@ -105,12 +110,20 @@ impl CaptureSink {
                 request: *request,
                 part: *part,
                 result: Ok(buffer),
+                permit: permit.clone(),
             })
             .is_ok()
     }
 }
 
 impl PendingScreencopy {
+    pub(crate) fn with_permit(mut self, permit: Option<super::screenshot::BudgetPermit>) -> Self {
+        if let CaptureSink::Owned { permit: stored, .. } = &mut self.sink {
+            *stored = permit;
+        }
+        self
+    }
+
     pub(crate) fn owned(
         request: u64,
         part: usize,
@@ -333,6 +346,19 @@ impl Ferese {
             .iter()
             .any(|capture| capture.output == *output && cursor_overlay_matches(capture.overlay_cursor, overlay_cursor))
     }
+
+    pub(crate) fn fail_screencopies(&mut self, output: &Output, overlay_cursor: bool) {
+        let mut remaining = Vec::new();
+        for capture in std::mem::take(&mut self.pending_screencopies) {
+            if capture.output == *output && cursor_overlay_matches(capture.overlay_cursor, overlay_cursor) {
+                capture.sink.fail();
+            } else {
+                remaining.push(capture);
+            }
+        }
+
+        self.pending_screencopies = remaining;
+    }
 }
 
 fn cursor_overlay_matches(requested: bool, rendered: bool) -> bool {

compositor/src/handlers/screenshot.rs

@@ -2,6 +2,10 @@
 
 use std::path::{Path, PathBuf};
 use std::sync::mpsc::SyncSender as ReplySender;
+use std::sync::{
+    Arc,
+    atomic::{AtomicUsize, Ordering},
+};
 use std::time::{Duration, Instant};
 
 use ferese_ipc::Response;
@@ -315,6 +319,7 @@ pub(crate) struct PartOutcome {
     pub(crate) request: u64,
     pub(crate) part: usize,
     pub(crate) result: Result<CaptureBuffer, String>,
+    pub(crate) permit: Option<BudgetPermit>,
 }
 
 // A calloop channel so publishing a part also wakes the event loop, whichever
@@ -352,11 +357,16 @@ struct Request {
     parts: Vec<(PartSpec, PartState)>,
     received: usize,
     deadline: Instant,
+    permit: Option<BudgetPermit>,
 }
 
 pub(crate) enum Action {
     None,
-    Encode { request: u64, frames: Vec<OutputFrame> },
+    Encode {
+        request: u64,
+        frames: Vec<OutputFrame>,
+        permit: BudgetPermit,
+    },
     // The path was already sent to the caller; it must not be cleaned up.
     Delivered(PathBuf),
     // The request is gone, so this file is ours to remove.
@@ -365,6 +375,45 @@ pub(crate) enum Action {
 
 const MAX_OUTSTANDING: usize = 8;
 const MAX_PENDING_BYTES: usize = 256 * 1024 * 1024;
+
+#[derive(Default, Debug)]
+struct Budget {
+    used: AtomicUsize,
+}
+
+#[derive(Debug)]
+struct Reservation {
+    budget: Arc<Budget>,
+    bytes: usize,
+}
+
+impl Drop for Reservation {
+    fn drop(&mut self) {
+        self.budget.used.fetch_sub(self.bytes, Ordering::AcqRel);
+    }
+}
+
+#[derive(Clone, Debug)]
+pub(crate) struct BudgetPermit {
+    _reservation: Arc<Reservation>,
+}
+
+impl Budget {
+    fn reserve(self: &Arc<Self>, bytes: usize) -> Result<BudgetPermit, String> {
+        self.used
+            .fetch_update(Ordering::AcqRel, Ordering::Acquire, |used| {
+                used.checked_add(bytes).filter(|total| *total <= MAX_PENDING_BYTES)
+            })
+            .map_err(|_| "Screenshot memory budget is exhausted".to_string())?;
+        Ok(BudgetPermit {
+            _reservation: Arc::new(Reservation {
+                budget: self.clone(),
+                bytes,
+            }),
+        })
+    }
+}
+
 // A request is answered or abandoned this long after it is admitted. Parts are
 // produced by the render path, so an output that is never repainted would
 // otherwise leave the request in Collecting forever, holding one of the few
@@ -375,6 +424,7 @@ pub(crate) const REQUEST_TIMEOUT: Duration = Duration::from_secs(30);
 pub(crate) struct Coordinator {
     requests: std::collections::HashMap<u64, Request>,
     next_id: u64,
+    budget: Arc<Budget>,
     deadline_changed: Option<Box<dyn Fn(Option<Instant>)>>,
     notified_deadline: Option<Instant>,
 }
@@ -432,6 +482,7 @@ impl Coordinator {
             return Err("Screenshot region is too large".into());
         }
 
+        let permit = self.budget.reserve(pending)?;
         self.next_id = self.next_id.wrapping_add(1);
         let id = self.next_id;
         self.requests.insert(
@@ -444,12 +495,17 @@ impl Coordinator {
                 parts: specs.into_iter().map(|spec| (spec, PartState::Pending)).collect(),
                 received: 0,
                 deadline: now + REQUEST_TIMEOUT,
+                permit: Some(permit),
             },
         );
         self.notify_deadline_change();
         Ok(id)
     }
 
+    pub(crate) fn permit(&self, request: u64) -> Option<BudgetPermit> {
+        self.requests.get(&request).and_then(|entry| entry.permit.clone())
+    }
+
     // Used by the completion tests to assert that a request is still tracked.
     #[allow(dead_code)]
     pub(crate) fn is_live(&self, request: u64) -> bool {
@@ -513,7 +569,11 @@ impl Coordinator {
             })
             .collect();
         entry.state = RequestState::Encoding;
-        Action::Encode { request, frames }
+        Action::Encode {
+            request,
+            frames,
+            permit: entry.permit.take().expect("collecting request owns its reservation"),
+        }
     }
 
     pub(crate) fn on_encoded(&mut self, request: u64, result: Result<PathBuf, String>) -> Action {
@@ -1045,6 +1105,43 @@ mod completion {
         ));
     }
 
+    #[test]
+    fn admission_enforces_one_budget_across_requests_and_late_readbacks() {
+        let (reply, _received) = sync_channel(8);
+        let mut coordinator = Coordinator::new();
+        let first = coordinator.admit(1, 1, reply.clone(), vec![spec(4096, 8192)]).unwrap();
+        let second = coordinator.admit(1, 2, reply.clone(), vec![spec(4096, 8192)]).unwrap();
+        assert!(coordinator.admit(1, 3, reply.clone(), vec![spec(2, 2)]).is_err());
+
+        // A cancelled request can still have a readback retained by a sink or channel.
+        let late_readback = coordinator.permit(first).unwrap();
+        coordinator.reject(first, "cancelled");
+        assert!(coordinator.admit(1, 4, reply.clone(), vec![spec(2, 2)]).is_err());
+        drop(late_readback);
+        assert!(coordinator.admit(1, 5, reply, vec![spec(2, 2)]).is_ok());
+        coordinator.reject(second, "finished");
+    }
+
+    #[test]
+    fn aggregate_reservations_survive_request_cancellation_during_encoding() {
+        let mut harness = Harness::new(1);
+        let id = harness.coordinator.next_id;
+        let bytes = harness.coordinator.budget.used.load(Ordering::Acquire);
+        let Action::Encode { frames, permit, .. } = harness.coordinator.on_part(id, 0, Ok(buffer(2, 2))) else {
+            panic!("ready request should encode");
+        };
+        harness.coordinator.reject(id, "cancelled while encoder owns pixels");
+        assert_eq!(harness.coordinator.budget.used.load(Ordering::Acquire), bytes);
+        assert!(harness.coordinator.budget.reserve(MAX_PENDING_BYTES).is_err());
+        drop(frames);
+        drop(permit);
+        assert_eq!(harness.coordinator.budget.used.load(Ordering::Acquire), 0);
+        let first = harness.coordinator.budget.reserve(MAX_PENDING_BYTES / 2 + 1).unwrap();
+        assert!(harness.coordinator.budget.reserve(MAX_PENDING_BYTES / 2).is_err());
+        drop(first);
+        assert!(harness.coordinator.budget.reserve(MAX_PENDING_BYTES).is_ok());
+    }
+
     #[test]
     fn all_parts_ready_hands_frames_to_the_encoder() {
         let mut harness = Harness::new(2);
@@ -1055,7 +1152,7 @@ mod completion {
             Action::None
         ));
         let action = harness.coordinator.on_part(id, 1, Ok(buffer(2, 2)));
-        let Action::Encode { request, frames } = action else {
+        let Action::Encode { request, frames, .. } = action else {
             panic!("expected the request to move to encoding");
         };
         assert_eq!(request, id);
@@ -1407,7 +1504,9 @@ mod completion {
         // buffer that was handed off is never replaced.
         assert!(!sink.publish(buffer(64, 64)));
 
-        let PartOutcome { request, part, result } = receiver.try_recv().expect("published once");
+        let PartOutcome {
+            request, part, result, ..
+        } = receiver.try_recv().expect("published once");
         assert_eq!((request, part), (7, 1));
         assert_eq!(result.unwrap().width, 2);
         assert!(receiver.try_recv().is_err(), "no second buffer was sent");
@@ -1422,7 +1521,9 @@ mod completion {
         // failure has already been reported.
         assert!(!sink.publish(buffer(2, 2)));
 
-        let PartOutcome { request, part, result } = receiver.try_recv().expect("answered");
+        let PartOutcome {
+            request, part, result, ..
+        } = receiver.try_recv().expect("answered");
         assert_eq!((request, part), (3, 0));
         assert!(result.is_err());
         assert!(receiver.try_recv().is_err());

compositor/src/handlers/screenshot_worker.rs

@@ -20,6 +20,7 @@ const FILE_MODE: u32 = 0o600;
 pub(crate) struct Job {
     pub(crate) request: u64,
     pub(crate) frames: Vec<OutputFrame>,
+    pub(crate) _permit: Option<super::screenshot::BudgetPermit>,
 }
 
 pub(crate) struct Encoded {
@@ -54,17 +55,13 @@ impl Worker {
 fn run(receiver: Receiver<Job>, results: channel::SyncSender<Encoded>) {
     while let Ok(job) = receiver.recv() {
         let result = encode(&job);
+        let request = job.request;
+        drop(job);
         // This send cannot block. Each request produces exactly one Encode, so at
         // most QUEUE_CAPACITY jobs can be queued while one more is being encoded,
         // and RESULT_QUEUE_CAPACITY is asserted to exceed that. Blocking here
         // would stall the worker with no way for the loop to recover it.
-        if results
-            .send(Encoded {
-                request: job.request,
-                result,
-            })
-            .is_err()
-        {
+        if results.send(Encoded { request, result }).is_err() {
             return;
         }
     }
@@ -131,25 +128,51 @@ fn encode_png(canvas: &Canvas) -> Result<Vec<u8>, String> {
 
 // The client is told to open this path and unlink it immediately, so the
 // directory is ours, private, and files are created with the final mode.
+struct StagedFile {
+    path: PathBuf,
+    keep: bool,
+}
+
+impl Drop for StagedFile {
+    fn drop(&mut self) {
+        if !self.keep {
+            let _ = fs::remove_file(&self.path);
+        }
+    }
+}
+
 fn write_private_file(png: &[u8]) -> Result<PathBuf, String> {
-    let directory = private_directory()?;
-    for attempt in 0..64u32 {
-        let path = directory.join(format!("shot-{}-{attempt}.png", std::process::id()));
-        let mut options = fs::OpenOptions::new();
-        options.write(true).create_new(true).mode(FILE_MODE);
-        match options.open(&path) {
-            Ok(mut file) => {
-                use io::Write;
-                file.write_all(png)
-                    .and_then(|()| file.sync_all())
-                    .map_err(|error| format!("Could not write screenshot: {error}"))?;
-                return Ok(path);
-            }
+    write_private_file_in(&private_directory()?, png, |file, bytes| {
+        use io::Write;
+        file.write_all(bytes)?;
+        file.sync_all()
+    })
+}
+
+fn write_private_file_in(
+    directory: &std::path::Path,
+    png: &[u8],
+    write: impl FnOnce(&mut fs::File, &[u8]) -> io::Result<()>,
+) -> Result<PathBuf, String> {
+    static NEXT_FILE: std::sync::atomic::AtomicU64 = std::sync::atomic::AtomicU64::new(0);
+    let (mut file, mut staged) = loop {
+        let sequence = NEXT_FILE.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+        let path = directory.join(format!("shot-{}-{sequence}.png", std::process::id()));
+        match fs::OpenOptions::new()
+            .write(true)
+            .create_new(true)
+            .mode(FILE_MODE)
+            .open(&path)
+        {
+            Ok(file) => break (file, StagedFile { path, keep: false }),
             Err(error) if error.kind() == io::ErrorKind::AlreadyExists => continue,
             Err(error) => return Err(format!("Could not write screenshot: {error}")),
         }
-    }
-    Err("Could not find an unused screenshot filename".into())
+    };
+
+    write(&mut file, png).map_err(|error| format!("Could not write screenshot: {error}"))?;
+    staged.keep = true;
+    Ok(std::mem::take(&mut staged.path))
 }
 
 fn private_directory() -> Result<PathBuf, String> {
@@ -209,6 +232,7 @@ mod tests {
         let job = Job {
             request: 1,
             frames: vec![frame(4, 3)],
+            _permit: None,
         };
         let mut canvas = compose(&job.frames).unwrap();
         for (index, pixel) in canvas.pixels.chunks_exact_mut(4).enumerate() {
@@ -227,6 +251,26 @@ mod tests {
         assert_eq!(decoded.get_pixel(0, 0)[3], 255);
     }
 
+    #[test]
+    fn staging_has_no_fixed_filename_capacity_and_cleans_partial_writes() {
+        let directory = tempfile::tempdir().unwrap();
+        for _ in 0..100 {
+            write_private_file_in(directory.path(), b"png", |file, bytes| {
+                use io::Write;
+                file.write_all(bytes)
+            })
+            .unwrap();
+        }
+        assert_eq!(fs::read_dir(directory.path()).unwrap().count(), 100);
+        let result = write_private_file_in(directory.path(), b"partial", |file, bytes| {
+            use io::Write;
+            file.write_all(bytes)?;
+            Err(io::Error::other("injected write/sync failure"))
+        });
+        assert!(result.is_err());
+        assert_eq!(fs::read_dir(directory.path()).unwrap().count(), 100);
+    }
+
     #[test]
     fn staged_files_are_owner_only() {
         let png = b"\x89PNG\r\n\x1a\nnot really a png".to_vec();

compositor/src/handlers/xdg_shell.rs

@@ -1,6 +1,6 @@
 use smithay::desktop::{
-    PopupKeyboardGrab, PopupKind, PopupManager, PopupPointerGrab, Space, Window, WindowSurfaceType,
-    find_popup_root_surface, get_popup_toplevel_coords,
+    PopupKeyboardGrab, PopupKind, PopupPointerGrab, Window, WindowSurfaceType, find_popup_root_surface,
+    get_popup_toplevel_coords,
 };
 use smithay::input::Seat;
 use smithay::input::pointer::{Focus, GrabStartData};
@@ -17,7 +17,7 @@ use smithay::wayland::shell::xdg::{
 };
 
 use crate::Ferese;
-use crate::grabs::{MoveSurfaceGrab, ResizeEdge, ResizeSurfaceGrab, handle_resize_commit};
+use crate::grabs::{MoveSurfaceGrab, ResizeEdge, ResizeSurfaceGrab};
 
 impl XdgShellHandler for Ferese {
     fn xdg_shell_state(&mut self) -> &mut XdgShellState {
@@ -82,19 +82,7 @@ impl XdgShellHandler for Ferese {
 
     fn toplevel_destroyed(&mut self, surface: ToplevelSurface) {
         // Hidden workspace windows are managed but unmapped from Space.
-        let Some(window) = self
-            .windows
-            .id_for_surface(surface.wl_surface())
-            .and_then(|id| self.windows.window(id))
-            .or_else(|| {
-                self.space.elements().find(|window| {
-                    window
-                        .toplevel()
-                        .is_some_and(|toplevel| toplevel.wl_surface() == surface.wl_surface())
-                })
-            })
-            .cloned()
-        else {
+        let Some(window) = self.window_for_surface(surface.wl_surface()) else {
             return;
         };
 
@@ -330,17 +318,27 @@ pub(crate) fn initial_configure_sent(toplevel: &ToplevelSurface) -> bool {
     })
 }
 
-pub fn handle_commit(popups: &mut PopupManager, space: &mut Space<Window>, surface: &WlSurface) {
-    handle_resize_commit(surface);
-    if let Some(window) = space
-        .elements()
-        .find(|window| {
-            window
-                .toplevel()
-                .is_some_and(|toplevel| toplevel.wl_surface() == surface)
-        })
-        .cloned()
-    {
+pub(crate) fn validate_size_constraints(toplevel: &ToplevelSurface) -> bool {
+    use smithay::reexports::wayland_protocols::xdg::shell::server::xdg_toplevel;
+    use smithay::wayland::shell::xdg::SurfaceCachedState;
+
+    let valid = with_states(toplevel.wl_surface(), |states| {
+        let mut cached = states.cached_state.get::<SurfaceCachedState>();
+        let state = cached.current();
+        let valid_axis = |min: i32, max: i32| min >= 0 && max >= 0 && (max == 0 || min <= max);
+        valid_axis(state.min_size.w, state.max_size.w) && valid_axis(state.min_size.h, state.max_size.h)
+    });
+    if !valid {
+        toplevel
+            .xdg_toplevel()
+            .post_error(xdg_toplevel::Error::InvalidSize, "invalid minimum/maximum window size");
+    }
+
+    valid
+}
+
+pub fn handle_commit(state: &mut Ferese, surface: &WlSurface) {
+    if let Some(window) = state.window_for_surface(surface) {
         let configured = with_states(surface, |states| {
             states
                 .data_map
@@ -358,8 +356,8 @@ pub fn handle_commit(popups: &mut PopupManager, space: &mut Space<Window>, surfa
         }
     }
 
-    popups.commit(surface);
-    if let Some(PopupKind::Xdg(popup)) = popups.find_popup(surface)
+    state.popups.commit(surface);
+    if let Some(PopupKind::Xdg(popup)) = state.popups.find_popup(surface)
         && !popup.is_initial_configure_sent()
     {
         popup.send_configure().expect("initial popup configure is valid");

compositor/src/input.rs

@@ -1,5 +1,3 @@
-use std::process::Command;
-
 use ferese_layout::Direction;
 use smithay::backend::input::{
     AbsolutePositionEvent, Axis, AxisSource, ButtonState, Event, GestureBeginEvent, GestureEndEvent,
@@ -22,6 +20,7 @@ use crate::Ferese;
 use crate::config::BindingAction;
 use crate::gestures::SwipeDirection;
 use crate::grabs::{MoveSurfaceGrab, ResizeEdge, ResizeSurfaceGrab};
+use crate::process::spawn_client;
 
 const BTN_LEFT: u32 = 0x110;
 const BTN_RIGHT: u32 = 0x111;
@@ -278,11 +277,16 @@ impl Ferese {
                         keyboard.set_focus(self, None, SERIAL_COUNTER.next_serial());
                     }
                 }
-                keyboard.input::<(), _>(
+                let serial = SERIAL_COUNTER.next_serial();
+                let interaction_focus = keyboard.current_focus();
+                let client_grab = keyboard
+                    .with_grab(|_, grab| grab.is::<smithay::desktop::PopupKeyboardGrab<Self>>())
+                    .unwrap_or(true);
+                let intercepted = keyboard.input::<(), _>(
                     self,
                     keycode,
                     state,
-                    SERIAL_COUNTER.next_serial(),
+                    serial,
                     event.time_msec(),
                     |data, modifiers, keysym| {
                         if data.focus_cycle.is_some() {
@@ -423,6 +427,10 @@ impl Ferese {
                         FilterResult::Intercept(())
                     },
                 );
+                if state == KeyState::Pressed && intercepted.is_none() && client_grab {
+                    self.record_activation_input(serial, interaction_focus);
+                }
+
                 if was_captured && !self.input_capture.active() {
                     self.restore_input_capture_focus();
                 }
@@ -534,6 +542,10 @@ impl Ferese {
                 if self.overview.is_active() {
                     let position = pointer.current_location();
                     if self.layer_under(position).is_some() {
+                        if event.state() == ButtonState::Pressed {
+                            self.record_activation_input(serial, pointer.current_focus());
+                        }
+
                         pointer.button(
                             self,
                             &ButtonEvent {
@@ -584,6 +596,16 @@ impl Ferese {
                     self.focus_window_at(pointer.current_location(), serial, true);
                 }
 
+                let client_grab = pointer
+                    .with_grab(|_, grab| {
+                        grab.is::<smithay::desktop::PopupPointerGrab<Self>>()
+                            || grab.is::<smithay::input::pointer::ClickGrab<Self>>()
+                    })
+                    .unwrap_or(true);
+                if event.state() == ButtonState::Pressed && client_grab {
+                    self.record_activation_input(serial, pointer.current_focus());
+                }
+
                 pointer.button(
                     self,
                     &ButtonEvent {
@@ -654,6 +676,10 @@ impl Ferese {
                 let touch = self.seat.get_touch().expect("seat has touch capability");
                 let serial = SERIAL_COUNTER.next_serial();
 
+                if !touch.is_grabbed() {
+                    self.record_activation_input(serial, self.surface_under(location).map(|(surface, _)| surface));
+                }
+
                 touch.down(
                     self,
                     self.surface_under(location),
@@ -1042,20 +1068,10 @@ impl Ferese {
         match action {
             BindingAction::None => {}
             BindingAction::Spawn(argv) => {
-                let (program, args) = argv.split_first().expect("binding commands are validated");
-
-                match Command::new(program)
-                    .args(args)
-                    .env("WAYLAND_DISPLAY", &self.socket_name)
-                    .env_remove("WAYLAND_SOCKET")
-                    .spawn()
+                if let Some(child) =
+                    spawn_client(self, argv.iter(), crate::private_client::ClientCapabilities::default())
                 {
-                    Ok(child) => {
-                        tracing::info!(%program, pid = child.id(), "spawned binding command")
-                    }
-                    Err(error) => {
-                        tracing::warn!(%program, %error, "failed to spawn binding command")
-                    }
+                    crate::process::watch_client_exit(&self.loop_handle, child);
                 }
             }
             BindingAction::Close => self.close_focused_window(),
@@ -1166,6 +1182,43 @@ fn overview_escape(symbol: u32, overview_active: bool) -> bool {
 mod tests {
     use super::{emergency_shortcut_escape, overview_escape, virtual_terminal};
 
+    #[test]
+    fn binding_commands_are_reaped_while_the_compositor_runs() {
+        if !crate::startup_tests::private_runtime("input::tests::binding_commands_are_reaped_while_the_compositor_runs")
+        {
+            return;
+        }
+
+        let mut events = smithay::reexports::calloop::EventLoop::try_new().unwrap();
+        let mut state = crate::startup_tests::state(&mut events);
+        let children_path = format!("/proc/self/task/{}/children", unsafe { libc::gettid() });
+        assert!(std::fs::read_to_string(&children_path).unwrap().trim().is_empty());
+        for _ in 0..24 {
+            state.execute_binding(crate::config::BindingAction::Spawn(vec!["/bin/true".into()].into()));
+        }
+
+        let children: Vec<i32> = std::fs::read_to_string(&children_path)
+            .unwrap()
+            .split_whitespace()
+            .map(|pid| pid.parse().unwrap())
+            .collect();
+        assert_eq!(children.len(), 24);
+        let deadline = std::time::Instant::now() + std::time::Duration::from_secs(3);
+        while !std::fs::read_to_string(&children_path).unwrap().trim().is_empty() {
+            assert!(std::time::Instant::now() < deadline, "binding children were not reaped");
+            events
+                .dispatch(Some(std::time::Duration::from_millis(20)), &mut state)
+                .unwrap();
+            crate::after_dispatch(&mut state);
+        }
+
+        for pid in children {
+            let mut status = 0;
+            assert_eq!(unsafe { libc::waitpid(pid, &mut status, libc::WNOHANG) }, -1);
+            assert_eq!(std::io::Error::last_os_error().raw_os_error(), Some(libc::ECHILD));
+        }
+    }
+
     #[test]
     fn escape_closes_only_an_active_overview() {
         assert!(overview_escape(keysyms::KEY_Escape, true));

compositor/src/ipc.rs

@@ -908,14 +908,16 @@ impl Ferese {
 
         for (position, part) in planned.iter().enumerate() {
             let (output, _) = &targets[part.index];
-            self.pending_screencopies
-                .push(crate::handlers::screencopy::PendingScreencopy::owned(
+            self.pending_screencopies.push(
+                crate::handlers::screencopy::PendingScreencopy::owned(
                     id,
                     position,
                     parts.clone(),
                     output.clone(),
                     part.buffer,
-                ));
+                )
+                .with_permit(self.screenshot.permit(id)),
+            );
         }
 
         // The nested backend redraws on its refresh timer; this drives the
@@ -1006,11 +1008,20 @@ impl Ferese {
             request: capture,
             part: 0,
             result,
+            permit: self.screenshot.permit(capture),
         });
     }
 
     pub(crate) fn on_screenshot_part(&mut self, outcome: PartOutcome) {
-        let action = self.screenshot.on_part(outcome.request, outcome.part, outcome.result);
+        let PartOutcome {
+            request,
+            part,
+            result,
+            permit,
+        } = outcome;
+        let action = self.screenshot.on_part(request, part, result);
+        // Pixels have moved into the coordinator/job before the channel lease is dropped.
+        drop(permit);
         self.apply_screenshot_action(action);
     }
 
@@ -1022,11 +1033,20 @@ impl Ferese {
     fn apply_screenshot_action(&mut self, action: Action) {
         match action {
             Action::None => {}
-            Action::Encode { request, frames } => {
-                let submitted = self
-                    .screenshot_worker
-                    .as_ref()
-                    .is_some_and(|worker| worker.submit(Job { request, frames }).is_ok());
+            Action::Encode {
+                request,
+                frames,
+                permit,
+            } => {
+                let submitted = self.screenshot_worker.as_ref().is_some_and(|worker| {
+                    worker
+                        .submit(Job {
+                            request,
+                            frames,
+                            _permit: Some(permit),
+                        })
+                        .is_ok()
+                });
                 if !submitted {
                     self.screenshot.reject(request, "Screenshot encoding queue is full");
                 }

compositor/src/main.rs

@@ -1,5 +1,3 @@
-#![allow(irrefutable_let_patterns)]
-
 mod backends;
 mod config;
 mod cursor;
@@ -26,6 +24,7 @@ mod portal_shortcuts;
 mod presentation;
 mod presentation_policy;
 mod private_client;
+mod process;
 mod reload;
 mod render;
 #[cfg(feature = "resize-metrics")]
@@ -35,6 +34,8 @@ mod resume;
 mod session_lock;
 mod shell_control;
 mod stacking;
+#[cfg(test)]
+mod startup_tests;
 mod state;
 mod theme;
 mod wallpaper;
@@ -42,11 +43,10 @@ mod window_rules;
 mod winit;
 
 use std::error::Error;
-use std::process::{Child, Command};
-use std::time::Duration;
-use std::{io, thread};
+use std::io;
 
 use calloop::signals::{Signal, Signals};
+use process::{spawn_client, terminate_child, watch_client_exit};
 use smithay::reexports::calloop::EventLoop;
 use smithay::reexports::wayland_server::Display;
 pub use state::{Ferese, RuntimeConfig};
@@ -64,13 +64,8 @@ fn main() -> Result<(), Box<dyn Error>> {
         if args.len() != 2 {
             return Err("usage: ferese --check-config PATH".into());
         }
-        let source = std::fs::read_to_string(&args[1])?;
-        theme::prepare(
-            &source,
-            std::path::Path::new(&args[1])
-                .parent()
-                .unwrap_or(std::path::Path::new(".")),
-        )?;
+
+        check_config(std::path::Path::new(&args[1]))?;
         println!("Configuration is valid");
         return Ok(());
     }
@@ -81,11 +76,10 @@ fn main() -> Result<(), Box<dyn Error>> {
         .filter(|path| path.exists())
         .map(|path| theme::read_source(&path))
         .transpose()?;
-    let source = initial_source.as_deref().unwrap_or("");
     let directory = config::config_path()
         .and_then(|path| path.parent().map(ToOwned::to_owned))
         .unwrap_or_else(|| std::path::PathBuf::from("."));
-    let (_, runtime, candidate) = theme::prepare(source, &directory)?;
+    let (_, runtime, candidate) = theme::prepare(initial_source.as_deref().unwrap_or(""), &directory)?;
     let mut event_loop = EventLoop::try_new()?;
     let signals = Signals::new(&[Signal::SIGINT, Signal::SIGTERM])?;
     event_loop
@@ -109,56 +103,18 @@ fn main() -> Result<(), Box<dyn Error>> {
             value
         });
     theme::init(&mut event_loop, &mut state, candidate)?;
-    resume::init(&mut event_loop)?;
+    let _resume_monitor = resume::init(&mut event_loop)?;
     idle_inhibition::media::init(&mut event_loop)?;
     overview::init_font_loader(&mut event_loop, &mut state)?;
     backends::init(launch.backend, &mut event_loop, &mut state)?;
+
     info!(socket = ?state.socket_name, backend = ?launch.backend, "Ferese is accepting Wayland clients");
-    let mut child = spawn_client(&mut state, launch.client, launch.client_capabilities);
+
+    let child = spawn_client(&mut state, launch.client, launch.client_capabilities)
+        .map(|child| watch_client_exit(&state.loop_handle, child));
     let runner = daemon::Runner::start(&mut state);
     state.daemons = Some(runner.clone());
-    let reload_handle = event_loop.handle();
-    let result = event_loop.run(None, &mut state, |state| {
-        state.poll_theme();
-        // The decoder wakes the loop after publishing its result, including
-        // when no output has a pending frame.
-        let wallpaper_changed = state.wallpaper.poll();
-        // All input/Wayland callbacks have returned, releasing seat locks.
-        if state.focus_cycle.is_some() && (state.session_lock.active() || state.input_capture.captures(1)) {
-            state.cancel_focus_cycle();
-        }
-        // Coalesce cursor changes and redraw here, never inside cursor_image.
-        if state.input_capture.restore_focus {
-            state.restore_input_capture_focus();
-        }
-        state.apply_unlocked_pointer_hint();
-        let wallpaper_retry = state.wallpaper.take_retry_wakeup();
-        let cursor_changed = std::mem::take(&mut state.cursor_redraw_pending);
-        let output_redraws = std::mem::take(&mut state.output_redraw_pending);
-        if wallpaper_changed || wallpaper_retry {
-            backends::direct::render_all(state);
-        } else {
-            if cursor_changed {
-                backends::direct::render_cursor(state);
-            }
-
-            if !output_redraws.is_empty() {
-                backends::direct::render_on(state, &output_redraws);
-            }
-        }
-        if let Err(error) = state
-            .wallpaper
-            .arm_retry_timer(&reload_handle, std::time::Instant::now())
-        {
-            warn!(%error, "could not schedule wallpaper upload retry");
-        }
-        // Registry/sync/configure replies must not depend on a submitted
-        // frame: at startup clients need these before they can draw anything.
-        // This also keeps idle DRM sessions responsive when there is no damage.
-        if let Err(error) = state.display_handle.flush_clients() {
-            tracing::warn!(%error, "failed to flush Wayland clients");
-        }
-    });
+    let result = event_loop.run(None, &mut state, after_dispatch);
 
     if let Some(backend) = state.direct_backend.as_ref() {
         backend.dump_scheduling_metrics();
@@ -168,8 +124,10 @@ fn main() -> Result<(), Box<dyn Error>> {
     state.resize_metrics.dump();
 
     runner.borrow_mut().stop();
-    if let Some(child) = &mut child {
-        terminate_child(child);
+    if let Some(child) = child
+        && let Some(mut child) = child.borrow_mut().take()
+    {
+        terminate_child(&mut child);
     }
 
     result.map_err(Into::into)
@@ -181,130 +139,66 @@ fn init_logging() {
     tracing_subscriber::fmt().with_env_filter(filter).init();
 }
 
-fn spawn_client(
-    state: &mut Ferese,
-    mut args: Vec<std::ffi::OsString>,
-    capabilities: private_client::ClientCapabilities,
-) -> Option<Child> {
-    if args.is_empty() {
-        info!("no client requested; pass one after `--`, for example `-- foot`");
-        return None;
-    }
-    let program = args.remove(0);
+fn check_config(path: &std::path::Path) -> Result<(), String> {
+    let source = theme::read_source(path)?;
+    theme::prepare(&source, path.parent().unwrap_or(std::path::Path::new(".")))?;
+    Ok(())
+}
 
-    let mut command = Command::new(&program);
-    command.args(args);
-    // Wallpaper decoding and drivers may already have worker threads. Set
-    // the child's display explicitly instead of mutating the process env.
-    command.env("WAYLAND_DISPLAY", &state.socket_name);
-    command.env_remove("WAYLAND_SOCKET");
-    command.env_remove("FERESE_SHELL_CONTROL_SOCKET");
-    command.env("FERESE_COMPOSITOR_WALLPAPER", "1");
-    let private_connection = if capabilities.is_empty() {
-        None
+#[derive(Debug)]
+enum RedrawRequest<'a> {
+    Global,
+    Cursor,
+    Outputs(&'a [smithay::output::Output]),
+}
+
+fn after_dispatch(state: &mut Ferese) {
+    after_dispatch_with_redraw(state, |state, request| match request {
+        RedrawRequest::Global => backends::direct::render_all(state),
+        RedrawRequest::Cursor => backends::direct::render_cursor(state),
+        RedrawRequest::Outputs(outputs) => backends::direct::render_on(state, outputs),
+    });
+}
+
+fn after_dispatch_with_redraw(state: &mut Ferese, mut redraw: impl FnMut(&mut Ferese, RedrawRequest<'_>)) {
+    state.poll_theme();
+    // The decoder wakes the loop after publishing its result, including
+    // when no output has a pending frame.
+    let wallpaper_changed = state.wallpaper.poll();
+    // All input/Wayland callbacks have returned, releasing seat locks.
+    if state.focus_cycle.is_some() && (state.session_lock.active() || state.input_capture.captures(1)) {
+        state.cancel_focus_cycle();
+    }
+
+    if state.input_capture.restore_focus {
+        state.restore_input_capture_focus();
+    }
+
+    state.apply_unlocked_pointer_hint();
+    let wallpaper_retry = state.wallpaper.take_retry_wakeup();
+    let cursor_changed = std::mem::take(&mut state.cursor_redraw_pending);
+    let output_redraws = std::mem::take(&mut state.output_redraw_pending);
+    if wallpaper_changed || wallpaper_retry {
+        redraw(state, RedrawRequest::Global);
     } else {
-        match private_client::prepare_command(state, &mut command, capabilities) {
-            Ok(connection) => Some(connection),
-            Err(error) => {
-                warn!(program = ?program, %error, "failed to create private Wayland connection");
-                return None;
-            }
+        if cursor_changed {
+            redraw(state, RedrawRequest::Cursor);
         }
-    };
 
-    let child = match command.spawn() {
-        Ok(child) => {
-            info!(program = ?program, pid = child.id(), "spawned Wayland client");
-            Some(child)
+        if !output_redraws.is_empty() {
+            redraw(state, RedrawRequest::Outputs(&output_redraws));
         }
-        Err(error) => {
-            warn!(program = ?program, %error, "failed to spawn Wayland client");
-            None
-        }
-    };
-    drop(private_connection);
-    child
-}
-
-fn terminate_child(child: &mut Child) {
-    if child.try_wait().ok().flatten().is_some() {
-        return;
     }
 
-    // SAFETY: the process ID comes from the live Child owned by Ferese.
-    unsafe {
-        libc::kill(child.id() as i32, libc::SIGTERM);
+    if let Err(error) = state
+        .wallpaper
+        .arm_retry_timer(&state.loop_handle, std::time::Instant::now())
+    {
+        warn!(%error, "could not schedule wallpaper upload retry");
     }
 
-    for _ in 0..20 {
-        if child.try_wait().ok().flatten().is_some() {
-            return;
-        }
-        thread::sleep(Duration::from_millis(10));
-    }
-
-    let _ = child.kill();
-    let _ = child.wait();
-}
-
-#[cfg(test)]
-mod startup_tests {
-    use std::io::{Read, Write};
-    use std::os::unix::net::UnixStream;
-    use std::sync::Arc;
-
-    use super::*;
-
-    #[test]
-    fn deferred_cursor_redraw_runs_after_input_lock_is_released() {
-        use std::sync::Mutex;
-
-        let mut event_loop = EventLoop::<bool>::try_new().unwrap();
-        let pointer_lock = Arc::new(Mutex::new(()));
-        let callback_lock = pointer_lock.clone();
-        event_loop.handle().insert_idle(move |pending| {
-            // Mirrors Smithay's cursor_image callback during pointer motion.
-            let _guard = callback_lock.lock().unwrap();
-            *pending = true;
-            *pending = true; // Multiple cursor changes must coalesce.
-            assert!(callback_lock.try_lock().is_err());
-        });
-
-        let signal = event_loop.get_signal();
-        let mut pending = false;
-        let mut redraws = 0;
-        event_loop
-            .run(Some(Duration::ZERO), &mut pending, |pending| {
-                if std::mem::take(pending) {
-                    // Rendering reads the pointer location at this point.
-                    let _guard = pointer_lock.try_lock().expect("input lock still held");
-                    redraws += 1;
-                }
-                assert!(!std::mem::take(pending));
-                signal.stop();
-            })
-            .unwrap();
-        assert_eq!(redraws, 1);
-    }
-
-    #[test]
-    fn wayland_roundtrip_completes_without_a_rendered_frame() {
-        let mut display = Display::<()>::new().unwrap();
-        let (server, mut client) = UnixStream::pair().unwrap();
-        display
-            .handle()
-            .insert_client(server, Arc::new(state::ClientState::default()))
-            .unwrap();
-        // wl_display.sync(new_id=2), using native-endian Wayland wire format.
-        for word in [1u32, 12u32 << 16, 2u32] {
-            client.write_all(&word.to_ne_bytes()).unwrap();
-        }
-        display.dispatch_clients(&mut ()).unwrap();
-        display.handle().flush_clients().unwrap();
-        client.set_read_timeout(Some(Duration::from_secs(1))).unwrap();
-        let mut reply = [0u8; 12];
-        client.read_exact(&mut reply).unwrap();
-        assert_eq!(u32::from_ne_bytes(reply[0..4].try_into().unwrap()), 2);
-        assert_eq!(u32::from_ne_bytes(reply[4..8].try_into().unwrap()) & 0xffff, 0);
+    // Clients need registry/sync/configure replies even when no frame is drawn.
+    if let Err(error) = state.display_handle.flush_clients() {
+        warn!(%error, "failed to flush Wayland clients");
     }
 }

compositor/src/process.rs

@@ -0,0 +1,172 @@
+use std::cell::RefCell;
+use std::ffi::OsStr;
+use std::io;
+use std::os::fd::{FromRawFd, OwnedFd};
+use std::os::unix::process::CommandExt;
+use std::process::{Child, Command};
+use std::rc::Rc;
+use std::time::Duration;
+
+use calloop::generic::Generic;
+use calloop::timer::{TimeoutAction, Timer};
+use calloop::{Interest, LoopHandle, Mode, PostAction};
+use tracing::{info, warn};
+
+use crate::Ferese;
+use crate::private_client::{self, ClientCapabilities};
+
+pub(crate) fn command(program: impl AsRef<OsStr>) -> Command {
+    let mut command = Command::new(program);
+    // Calloop blocks these on the compositor thread; fork/exec inherits that
+    // mask. Leave unrelated signal masks alone, including those of the launcher.
+    // SAFETY: only async-signal-safe signal-set operations run between fork and exec.
+    unsafe {
+        command.pre_exec(|| {
+            let mut mask = std::mem::zeroed();
+            libc::sigemptyset(&mut mask);
+            libc::sigaddset(&mut mask, libc::SIGINT);
+            libc::sigaddset(&mut mask, libc::SIGTERM);
+            if libc::sigprocmask(libc::SIG_UNBLOCK, &mask, std::ptr::null_mut()) == -1 {
+                return Err(io::Error::last_os_error());
+            }
+
+            Ok(())
+        });
+    }
+
+    command
+}
+
+pub(crate) fn spawn_client<S: AsRef<OsStr>>(
+    state: &mut Ferese,
+    args: impl IntoIterator<Item = S>,
+    capabilities: ClientCapabilities,
+) -> Option<Child> {
+    let mut args = args.into_iter();
+    let Some(program) = args.next() else {
+        info!("no client requested; pass one after `--`, for example `-- foot`");
+        return None;
+    };
+
+    let program = program.as_ref();
+    let mut command = command(program);
+    command.args(args);
+    // Workers may already exist. Change only this child's environment.
+    command.env("WAYLAND_DISPLAY", &state.socket_name);
+    command.env_remove("WAYLAND_SOCKET");
+    command.env_remove("FERESE_SHELL_CONTROL_SOCKET");
+    command.env("FERESE_COMPOSITOR_WALLPAPER", "1");
+    let private_connection = if capabilities.is_empty() {
+        None
+    } else {
+        match private_client::prepare_command(state, &mut command, capabilities) {
+            Ok(connection) => Some(connection),
+            Err(error) => {
+                warn!(program = ?program, %error, "failed to create private Wayland connection");
+                return None;
+            }
+        }
+    };
+
+    let child = match command.spawn() {
+        Ok(child) => {
+            info!(program = ?program, pid = child.id(), "spawned Wayland client");
+            Some(child)
+        }
+        Err(error) => {
+            warn!(program = ?program, %error, "failed to spawn Wayland client");
+            None
+        }
+    };
+    drop(private_connection);
+    child
+}
+
+pub(crate) fn pidfd(pid: u32) -> io::Result<OwnedFd> {
+    // SAFETY: pidfd_open has no pointer arguments and returns a new owned fd.
+    let fd = unsafe { libc::syscall(libc::SYS_pidfd_open, pid, 0) };
+    if fd < 0 {
+        return Err(io::Error::last_os_error());
+    }
+
+    // SAFETY: a successful syscall returned a unique valid descriptor.
+    Ok(unsafe { OwnedFd::from_raw_fd(fd as i32) })
+}
+
+fn reap(child: &RefCell<Option<Child>>) -> bool {
+    let mut child = child.borrow_mut();
+    let Some(process) = child.as_mut() else {
+        return true;
+    };
+
+    match process.try_wait() {
+        Ok(Some(status)) => {
+            info!(pid = process.id(), %status, "Wayland client exited");
+            *child = None;
+            true
+        }
+        Ok(None) => false,
+        Err(error) => {
+            warn!(%error, "cannot reap Wayland client");
+            false
+        }
+    }
+}
+
+pub(crate) fn watch_client_exit(handle: &LoopHandle<'static, Ferese>, child: Child) -> Rc<RefCell<Option<Child>>> {
+    let pid = child.id();
+    let owner = Rc::new(RefCell::new(Some(child)));
+    let watched = owner.clone();
+    let result = pidfd(pid).and_then(|fd| {
+        handle
+            .insert_source(Generic::new(fd, Interest::READ, Mode::Level), move |_, _, _| {
+                Ok(if reap(&watched) {
+                    PostAction::Remove
+                } else {
+                    PostAction::Continue
+                })
+            })
+            .map_err(io::Error::other)
+    });
+
+    if let Err(error) = result {
+        warn!(%error, pid, "could not watch client exit with pidfd; polling instead");
+        let watched = owner.clone();
+        if let Err(error) = handle.insert_source(Timer::from_duration(Duration::from_millis(250)), move |_, _, _| {
+            if reap(&watched) {
+                TimeoutAction::Drop
+            } else {
+                TimeoutAction::ToDuration(Duration::from_millis(250))
+            }
+        }) {
+            warn!(%error, pid, "could not schedule client exit polling; stopping child");
+            if let Some(mut child) = owner.borrow_mut().take() {
+                terminate_child(&mut child);
+            }
+        }
+    }
+
+    owner
+}
+
+pub(crate) fn terminate_child(child: &mut Child) {
+    if child.try_wait().ok().flatten().is_some() {
+        return;
+    }
+
+    // SAFETY: the process ID comes from the live Child owned by Ferese.
+    unsafe {
+        libc::kill(child.id() as i32, libc::SIGTERM);
+    }
+
+    for _ in 0..20 {
+        if child.try_wait().ok().flatten().is_some() {
+            return;
+        }
+
+        std::thread::sleep(Duration::from_millis(10));
+    }
+
+    let _ = child.kill();
+    let _ = child.wait();
+}

compositor/src/resume.rs

@@ -1,57 +1,257 @@
-//! System wake is shared by hardware reconciliation and time-dependent UI state.
+//! System wake and listener recovery share reconciliation, but not idle activity.
 use std::error::Error;
+use std::sync::{Arc, Condvar, Mutex};
+use std::task::{Poll, Waker};
+use std::thread::JoinHandle;
 use std::time::Duration;
 
-use calloop::EventLoop;
 use calloop::channel::{Event, channel};
+use calloop::{EventLoop, LoopHandle, RegistrationToken};
+use futures_lite::{StreamExt, future};
 
 use crate::Ferese;
 
-pub(crate) fn init(event_loop: &mut EventLoop<Ferese>) -> Result<(), Box<dyn Error>> {
+const RETRY_DELAY: Duration = Duration::from_secs(5);
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+enum Refresh {
+    Resumed,
+    Reconcile,
+}
+
+#[derive(Debug, PartialEq, Eq)]
+enum MonitorExit {
+    Stop,
+    Reconnect,
+}
+
+#[derive(Default)]
+struct StopState {
+    requested: bool,
+    waker: Option<Waker>,
+}
+
+#[derive(Default)]
+struct Cancellation {
+    state: Mutex<StopState>,
+    changed: Condvar,
+}
+
+impl Cancellation {
+    fn cancel(&self) {
+        let mut state = self.state.lock().unwrap();
+        state.requested = true;
+        let waker = state.waker.take();
+        self.changed.notify_all();
+        drop(state);
+
+        if let Some(waker) = waker {
+            waker.wake();
+        }
+    }
+
+    async fn cancelled(&self) {
+        future::poll_fn(|context| {
+            let mut state = self.state.lock().unwrap();
+            if state.requested {
+                return Poll::Ready(());
+            }
+
+            state.waker = Some(context.waker().clone());
+            Poll::Pending
+        })
+        .await;
+    }
+
+    fn retry(&self, delay: Duration) -> bool {
+        let (state, _) = self
+            .changed
+            .wait_timeout_while(self.state.lock().unwrap(), delay, |state| !state.requested)
+            .unwrap();
+        !state.requested
+    }
+}
+
+pub(crate) struct Monitor {
+    stop: Arc<Cancellation>,
+    worker: Option<JoinHandle<()>>,
+    source: Option<(LoopHandle<'static, Ferese>, RegistrationToken)>,
+}
+
+impl Drop for Monitor {
+    fn drop(&mut self) {
+        self.stop.cancel();
+        if let Some((handle, token)) = self.source.take() {
+            handle.remove(token);
+        }
+
+        // Cancellation wakes both the signal wait and retry delay. Do not join
+        // a DBus worker on the compositor thread during shutdown.
+        self.worker.take();
+    }
+}
+
+fn refresh(state: &mut Ferese, event: Refresh) {
+    match event {
+        Refresh::Resumed => crate::backends::direct::system_resumed(state),
+        Refresh::Reconcile => crate::backends::direct::reconcile_after_monitor_recovery(state),
+    }
+
+    state.refresh_theme();
+}
+
+pub(crate) fn init(event_loop: &mut EventLoop<'static, Ferese>) -> Result<Monitor, Box<dyn Error>> {
     let (sender, receiver) = channel();
-    event_loop.handle().insert_source(receiver, |event, _, state| {
-        if let Event::Msg(()) = event {
-            crate::backends::direct::system_resumed(state);
-            state.refresh_theme();
+    let handle = event_loop.handle();
+    let token = handle.insert_source(receiver, |event, _, state| {
+        if let Event::Msg(event) = event {
+            refresh(state, event);
         }
     })?;
 
-    std::thread::Builder::new()
+    match start(zbus::connection::Builder::system, RETRY_DELAY, move |event| {
+        sender.send(event).is_ok()
+    }) {
+        Ok(mut monitor) => {
+            monitor.source = Some((handle, token));
+            Ok(monitor)
+        }
+        Err(error) => {
+            handle.remove(token);
+            Err(error.into())
+        }
+    }
+}
+
+#[derive(Default)]
+struct Recovery {
+    reconnecting: bool,
+    warned: bool,
+}
+
+impl Recovery {
+    fn unavailable(&mut self) -> bool {
+        self.reconnecting = true;
+        let warn = !self.warned;
+        self.warned = true;
+        warn
+    }
+
+    fn subscribed(&mut self) -> bool {
+        self.warned = false;
+        std::mem::take(&mut self.reconnecting)
+    }
+}
+
+fn start(
+    connect: impl Fn() -> zbus::Result<zbus::connection::Builder<'static>> + Send + 'static,
+    retry_delay: Duration,
+    mut send: impl FnMut(Refresh) -> bool + Send + 'static,
+) -> std::io::Result<Monitor> {
+    let stop = Arc::new(Cancellation::default());
+    let worker_stop = stop.clone();
+    let worker = std::thread::Builder::new()
         .name("ferese-system-resume".into())
         .spawn(move || {
-            let mut warned = false;
+            let mut recovery = Recovery::default();
             loop {
-                let monitor = || -> zbus::Result<bool> {
-                    let connection = zbus::blocking::connection::Builder::system()?
-                        .method_timeout(Duration::from_secs(2))
-                        .build()?;
-                    let proxy = zbus::blocking::Proxy::new(
-                        &connection,
-                        "org.freedesktop.login1",
-                        "/org/freedesktop/login1",
-                        "org.freedesktop.login1.Manager",
-                    )?;
-                    for message in proxy.receive_signal("PrepareForSleep")? {
-                        let (sleeping,): (bool,) = message.body().deserialize()?;
-                        if !sleeping && sender.send(()).is_err() {
-                            return Ok(false);
+                let result = future::block_on(future::race(
+                    async {
+                        worker_stop.cancelled().await;
+                        Ok(MonitorExit::Stop)
+                    },
+                    async {
+                        let connection = connect()?.method_timeout(Duration::from_secs(2)).build().await?;
+                        future::race(
+                            async {
+                                connection.closed().await;
+                                Ok(MonitorExit::Reconnect)
+                            },
+                            listen(&connection, &mut recovery, &mut send),
+                        )
+                        .await
+                    },
+                ));
+
+                match result {
+                    Ok(MonitorExit::Stop) => break,
+                    Ok(MonitorExit::Reconnect) => {
+                        if recovery.unavailable() {
+                            tracing::warn!("system resume monitoring interrupted; retrying connection");
                         }
                     }
-                    Ok(true)
-                };
-
-                match monitor() {
-                    Ok(false) => break,
-                    Ok(true) => warned = false,
-                    Err(error) if !warned => {
-                        tracing::warn!(%error, "system resume monitor unavailable; retrying connection");
-                        warned = true;
+                    Err(error) => {
+                        if recovery.unavailable() {
+                            tracing::warn!(%error, "system resume monitor unavailable; retrying connection");
+                        }
                     }
-                    Err(_) => {}
                 }
-                // Recovery only: a healthy listener blocks on DBus signals.
-                std::thread::sleep(Duration::from_secs(5));
+
+                if !worker_stop.retry(retry_delay) {
+                    break;
+                }
             }
         })?;
-    Ok(())
+
+    Ok(Monitor {
+        stop,
+        worker: Some(worker),
+        source: None,
+    })
 }
+
+async fn listen(
+    connection: &zbus::Connection,
+    recovery: &mut Recovery,
+    send: &mut impl FnMut(Refresh) -> bool,
+) -> zbus::Result<MonitorExit> {
+    let proxy = zbus::Proxy::new(
+        connection,
+        "org.freedesktop.login1",
+        "/org/freedesktop/login1",
+        "org.freedesktop.login1.Manager",
+    )
+    .await?;
+    let mut owners = proxy.receive_owner_changed().await?;
+    let mut signals = proxy.receive_signal("PrepareForSleep").await?;
+    // AddMatch succeeds even when logind is absent. Only call the listener
+    // recovered once the service is present, and retry if its owner changes.
+    connection
+        .call_method(
+            Some("org.freedesktop.DBus"),
+            "/org/freedesktop/DBus",
+            Some("org.freedesktop.DBus"),
+            "GetNameOwner",
+            &("org.freedesktop.login1",),
+        )
+        .await?;
+
+    // Subscribe first: a resume during reconciliation must remain queued.
+    if recovery.subscribed() {
+        tracing::debug!("system resume monitoring recovered; reconciling current state");
+        if !send(Refresh::Reconcile) {
+            return Ok(MonitorExit::Stop);
+        }
+    }
+
+    future::race(
+        async {
+            owners.next().await;
+            Ok(MonitorExit::Reconnect)
+        },
+        async {
+            while let Some(message) = signals.next().await {
+                let (sleeping,): (bool,) = message.body().deserialize()?;
+                if !sleeping && !send(Refresh::Resumed) {
+                    return Ok(MonitorExit::Stop);
+                }
+            }
+
+            Ok(MonitorExit::Reconnect)
+        },
+    )
+    .await
+}
+
+#[cfg(test)]
+mod tests;

compositor/src/resume/tests.rs

@@ -0,0 +1,249 @@
+use std::io::{BufRead, BufReader};
+use std::process::{Child, Stdio};
+use std::sync::mpsc::{self, Receiver};
+use std::time::Instant;
+
+use super::*;
+
+#[test]
+fn warning_suppression_resets_at_subscription_not_at_next_resume() {
+    let mut recovery = Recovery::default();
+    assert!(!recovery.subscribed(), "startup is not a recovery or a resume");
+    assert!(recovery.unavailable());
+    assert!(!recovery.unavailable(), "one warning per outage");
+    assert!(recovery.subscribed());
+    assert!(!recovery.subscribed(), "one reconciliation per recovery");
+    assert!(recovery.unavailable(), "another outage must warn even without a resume");
+    assert!(!recovery.unavailable());
+}
+
+fn stop_and_join(mut monitor: Monitor) {
+    let worker = monitor.worker.take().unwrap();
+    drop(monitor);
+    let deadline = Instant::now() + Duration::from_secs(1);
+    while !worker.is_finished() && Instant::now() < deadline {
+        std::thread::sleep(Duration::from_millis(2));
+    }
+
+    assert!(worker.is_finished(), "cancellation did not stop the worker promptly");
+    worker.join().unwrap();
+}
+
+#[test]
+fn shutdown_interrupts_retry_delay() {
+    let (attempt, attempted) = mpsc::channel();
+    let monitor = start(
+        move || {
+            attempt.send(()).unwrap();
+            Err(zbus::Error::Failure("test connection failure".into()))
+        },
+        RETRY_DELAY,
+        |_| panic!("no subscription succeeded"),
+    )
+    .unwrap();
+    attempted.recv_timeout(Duration::from_secs(1)).unwrap();
+    stop_and_join(monitor);
+    assert!(
+        attempted.try_recv().is_err(),
+        "shutdown must not start another connection"
+    );
+}
+
+struct Bus {
+    process: Child,
+    address: String,
+}
+
+impl Bus {
+    fn new() -> Self {
+        let mut process = crate::process::command("dbus-daemon")
+            .args(["--session", "--nofork", "--print-address=1"])
+            .stdout(Stdio::piped())
+            .spawn()
+            .unwrap();
+        let mut address = String::new();
+        BufReader::new(process.stdout.take().unwrap())
+            .read_line(&mut address)
+            .unwrap();
+        Self {
+            process,
+            address: address.trim().to_owned(),
+        }
+    }
+
+    fn stop(&mut self) {
+        let _ = self.process.kill();
+        let _ = self.process.wait();
+    }
+
+    fn manager(&self) -> zbus::blocking::Connection {
+        struct Manager;
+        #[zbus::interface(name = "org.freedesktop.login1.Manager")]
+        impl Manager {
+            #[zbus(property)]
+            fn lid_closed(&self) -> bool {
+                false
+            }
+        }
+
+        zbus::blocking::connection::Builder::address(self.address.as_str())
+            .unwrap()
+            .name("org.freedesktop.login1")
+            .unwrap()
+            .serve_at("/org/freedesktop/login1", Manager)
+            .unwrap()
+            .build()
+            .unwrap()
+    }
+}
+
+impl Drop for Bus {
+    fn drop(&mut self) {
+        self.stop();
+    }
+}
+
+fn signal(manager: &zbus::blocking::Connection, sleeping: bool) {
+    manager
+        .emit_signal(
+            None::<&str>,
+            "/org/freedesktop/login1",
+            "org.freedesktop.login1.Manager",
+            "PrepareForSleep",
+            &(sleeping,),
+        )
+        .unwrap();
+}
+
+fn confirm_subscription(manager: &zbus::blocking::Connection, events: &Receiver<Refresh>) {
+    let deadline = Instant::now() + Duration::from_secs(2);
+    loop {
+        signal(manager, false);
+        if let Ok(event) = events.recv_timeout(Duration::from_millis(10)) {
+            assert_eq!(event, Refresh::Resumed);
+            break;
+        }
+
+        assert!(Instant::now() < deadline, "listener did not subscribe");
+    }
+}
+
+#[test]
+fn reconnect_reconciles_a_resume_missed_during_the_outage() {
+    if !crate::startup_tests::private_runtime("resume::tests::reconnect_reconciles_a_resume_missed_during_the_outage") {
+        return;
+    }
+
+    let mut bus = Bus::new();
+    let manager = bus.manager();
+    let address = Arc::new(Mutex::new(bus.address.clone()));
+    let worker_address = address.clone();
+    let (sender, events) = mpsc::channel();
+    let (attempt, attempts) = mpsc::channel();
+    let monitor = start(
+        move || {
+            attempt.send(()).unwrap();
+            zbus::connection::Builder::address(worker_address.lock().unwrap().as_str())
+        },
+        Duration::from_millis(40),
+        move |event| sender.send(event).is_ok(),
+    )
+    .unwrap();
+    confirm_subscription(&manager, &events);
+    attempts.recv_timeout(Duration::from_secs(1)).unwrap();
+    *address.lock().unwrap() = "unix:path=/nonexistent/ferese-test-bus".into();
+    bus.stop();
+    attempts.recv_timeout(Duration::from_secs(1)).unwrap();
+
+    let replacement = Bus::new();
+    let manager = replacement.manager();
+    signal(&manager, false); // No listener can receive this resume.
+    *address.lock().unwrap() = replacement.address.clone();
+    assert_eq!(events.recv_timeout(Duration::from_secs(2)).unwrap(), Refresh::Reconcile);
+    assert!(events.recv_timeout(Duration::from_millis(80)).is_err());
+    signal(&manager, true);
+    assert!(events.recv_timeout(Duration::from_millis(40)).is_err());
+    signal(&manager, false);
+    assert_eq!(events.recv_timeout(Duration::from_secs(1)).unwrap(), Refresh::Resumed);
+    stop_and_join(monitor);
+}
+
+#[test]
+fn shutdown_interrupts_a_healthy_signal_wait() {
+    if !crate::startup_tests::private_runtime("resume::tests::shutdown_interrupts_a_healthy_signal_wait") {
+        return;
+    }
+
+    let bus = Bus::new();
+    let manager = bus.manager();
+    let address = bus.address.clone();
+    let (sender, events) = mpsc::channel();
+    let monitor = start(
+        move || zbus::connection::Builder::address(address.as_str()),
+        RETRY_DELAY,
+        move |event| sender.send(event).is_ok(),
+    )
+    .unwrap();
+    confirm_subscription(&manager, &events);
+    stop_and_join(monitor);
+}
+
+#[test]
+fn logind_replacement_reconciles_without_a_bus_disconnect() {
+    if !crate::startup_tests::private_runtime("resume::tests::logind_replacement_reconciles_without_a_bus_disconnect") {
+        return;
+    }
+
+    let bus = Bus::new();
+    let manager = bus.manager();
+    let address = bus.address.clone();
+    let (sender, events) = mpsc::channel();
+    let monitor = start(
+        move || zbus::connection::Builder::address(address.as_str()),
+        Duration::from_millis(40),
+        move |event| sender.send(event).is_ok(),
+    )
+    .unwrap();
+    confirm_subscription(&manager, &events);
+    manager.release_name("org.freedesktop.login1").unwrap();
+    assert!(
+        events.recv_timeout(Duration::from_millis(100)).is_err(),
+        "absent logind is not recovery"
+    );
+    let replacement = bus.manager();
+    assert_eq!(events.recv_timeout(Duration::from_secs(2)).unwrap(), Refresh::Reconcile);
+    signal(&replacement, false);
+    assert_eq!(events.recv_timeout(Duration::from_secs(1)).unwrap(), Refresh::Resumed);
+    stop_and_join(monitor);
+}
+
+#[test]
+fn shutdown_interrupts_connection_authentication() {
+    if !crate::startup_tests::private_runtime("resume::tests::shutdown_interrupts_connection_authentication") {
+        return;
+    }
+
+    let directory = tempfile::tempdir().unwrap();
+    let path = directory.path().join("silent-bus");
+    let listener = std::os::unix::net::UnixListener::bind(&path).unwrap();
+    listener.set_nonblocking(true).unwrap();
+    let address = format!("unix:path={}", path.display());
+    let monitor = start(
+        move || zbus::connection::Builder::address(address.as_str()),
+        RETRY_DELAY,
+        |_| panic!("authentication cannot complete"),
+    )
+    .unwrap();
+    let deadline = Instant::now() + Duration::from_secs(1);
+    let _connection = loop {
+        match listener.accept() {
+            Ok((stream, _)) => break stream,
+            Err(error) if error.kind() == std::io::ErrorKind::WouldBlock => {
+                assert!(Instant::now() < deadline);
+                std::thread::sleep(Duration::from_millis(2));
+            }
+            Err(error) => panic!("{error}"),
+        }
+    };
+    stop_and_join(monitor);
+}

compositor/src/session_lock.rs

@@ -111,7 +111,7 @@ pub(crate) struct Lock {
     pub(crate) idle_opacity: f32,
     pub(crate) sleeping: bool,
     pub(crate) idle_overlays: HashMap<Output, smithay::backend::renderer::element::solid::SolidColorBuffer>,
-    idle_timer: Option<RegistrationToken>,
+    idle_timer: Option<(RegistrationToken, Instant)>,
 }
 
 impl Lock {
@@ -130,6 +130,8 @@ impl Lock {
     pub(crate) fn output_removed(&mut self, output: &Output) {
         self.presented.remove(output);
         self.idle_overlays.remove(output);
+        self.surfaces.remove(output);
+        self.backgrounds.remove(output);
     }
 
     fn activity(&mut self, now: Instant) -> bool {
@@ -167,7 +169,11 @@ impl Ferese {
             crate::backends::direct::wake_locked_outputs(self);
             self.cursor_redraw_pending = true;
         }
-        self.rearm_lock_idle();
+        // Activity moves the deadline later. Keep the existing source and let
+        // it recheck idle_since when it fires. Sleeping outputs have no timer.
+        if self.session_lock.idle_timer.is_none() {
+            self.rearm_lock_idle();
+        }
     }
 
     pub(crate) fn refresh_lock_idle_policy(&mut self) {
@@ -175,32 +181,52 @@ impl Ferese {
         self.rearm_lock_idle();
     }
 
-    fn rearm_lock_idle(&mut self) {
-        if let Some(token) = self.session_lock.idle_timer.take() {
-            self.loop_handle.remove(token);
-        }
+    fn lock_idle_deadline(&self, now: Instant) -> Option<Instant> {
         if !self.lock_outputs_protected() {
-            return;
+            return None;
         }
 
         let elapsed = self
             .session_lock
             .idle_since
-            .map_or(Duration::ZERO, |since| since.elapsed());
-        let Some(delay) = self
-            .lock_idle
+            .map_or(Duration::ZERO, |since| now.saturating_duration_since(since));
+        self.lock_idle
             .next_deadline(elapsed, self.animation_duration(Duration::from_millis(500)))
-        else {
+            .map(|delay| now + delay)
+    }
+
+    fn rearm_lock_idle(&mut self) {
+        let deadline = self.lock_idle_deadline(Instant::now());
+        if let Some((_, armed)) = self.session_lock.idle_timer
+            && deadline.is_some_and(|deadline| armed <= deadline)
+        {
+            return;
+        }
+
+        if let Some((token, _)) = self.session_lock.idle_timer.take() {
+            self.loop_handle.remove(token);
+        }
+
+        let Some(deadline) = deadline else {
             return;
         };
         match self
             .loop_handle
-            .insert_source(Timer::from_duration(delay), |_, _, state| {
-                state.session_lock.idle_timer = None;
-                state.refresh_lock_idle_policy();
-                TimeoutAction::Drop
+            .insert_source(Timer::from_deadline(deadline), |_, _, state| {
+                let now = Instant::now();
+                state.update_lock_idle(now);
+                if let Some(deadline) = state.lock_idle_deadline(now) {
+                    if let Some((_, armed)) = state.session_lock.idle_timer.as_mut() {
+                        *armed = deadline;
+                    }
+
+                    TimeoutAction::ToInstant(deadline)
+                } else {
+                    state.session_lock.idle_timer = None;
+                    TimeoutAction::Drop
+                }
             }) {
-            Ok(token) => self.session_lock.idle_timer = Some(token),
+            Ok(token) => self.session_lock.idle_timer = Some((token, deadline)),
             Err(error) => tracing::warn!(%error, "could not arm lock idle deadline"),
         }
     }
@@ -251,8 +277,17 @@ impl Ferese {
         let surface = self
             .focused_output()
             .and_then(|output| self.session_lock.surfaces.get(output))
-            .or_else(|| self.session_lock.surfaces.values().find(|surface| surface.alive()))
             .filter(|surface| surface.alive())
+            .or_else(|| {
+                // Stable output IDs keep fallback focus independent of HashMap order.
+                self.session_lock
+                    .surfaces
+                    .iter()
+                    .filter(|(_, surface)| surface.alive())
+                    .filter_map(|(output, surface)| self.output_id(output).map(|id| (id, surface)))
+                    .min_by_key(|(id, _)| *id)
+                    .map(|(_, surface)| surface)
+            })
             .map(|surface| surface.wl_surface().clone());
         self.seat
             .get_keyboard()
@@ -378,7 +413,7 @@ impl SessionLockHandler for Ferese {
     }
 
     fn unlock(&mut self) {
-        if let Some(timer) = self.session_lock.idle_timer.take() {
+        if let Some((timer, _)) = self.session_lock.idle_timer.take() {
             self.loop_handle.remove(timer);
         }
         let sleeping = self.session_lock.sleeping;
@@ -456,346 +491,4 @@ smithay::reexports::wayland_server::delegate_dispatch!(Ferese: [ExtSessionLockMa
 smithay::reexports::wayland_server::delegate_dispatch!(Ferese: [ExtSessionLockSurfaceV1: smithay::wayland::session_lock::ExtLockSurfaceUserData] => SessionLockManagerState);
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    #[ignore = "requires a private XDG_RUNTIME_DIR and permission to bind test sockets"]
-    fn zero_outputs_confirm_and_dead_owner_can_be_replaced_without_unlocking() {
-        use std::io::{Read, Write};
-        use std::os::unix::net::UnixStream;
-        use std::sync::Arc;
-
-        use smithay::reexports::calloop::EventLoop;
-        use smithay::reexports::wayland_server::Display;
-
-        let runtime = std::path::PathBuf::from(std::env::var_os("XDG_RUNTIME_DIR").unwrap());
-        assert!(runtime.starts_with(std::env::temp_dir()));
-        let mut event_loop = EventLoop::try_new().unwrap();
-        let config = crate::config::Config::default().runtime_config().unwrap();
-        let mut state = Ferese::new(&mut event_loop, Display::new().unwrap(), config).unwrap();
-        let capture_epoch = state.capture_epoch;
-
-        let acquire = |state: &mut Ferese| {
-            let (server, mut wire) = UnixStream::pair().unwrap();
-            let client = state
-                .display_handle
-                .insert_client(server, Arc::new(crate::state::ClientState::default()))
-                .unwrap();
-            let manager = client
-                .create_resource::<ExtSessionLockManagerV1, (), Ferese>(&state.display_handle, 1, ())
-                .unwrap();
-            // ext_session_lock_manager_v1.lock(new_id=2).
-            for word in [manager.id().protocol_id(), (12u32 << 16) | 1, 2] {
-                wire.write_all(&word.to_ne_bytes()).unwrap();
-            }
-            wire
-        };
-        let dispatch = |event_loop: &mut EventLoop<'static, Ferese>, state: &mut Ferese| {
-            event_loop.dispatch(Duration::from_millis(20), state).unwrap();
-            state.display_handle.flush_clients().unwrap();
-        };
-
-        let mut first = acquire(&mut state);
-        dispatch(&mut event_loop, &mut state);
-        assert_ne!(
-            state.capture_epoch, capture_epoch,
-            "lock revokes deferred window snapshots"
-        );
-        assert!(
-            matches!(state.session_lock.lifecycle, Lifecycle::Locked(_)),
-            "no outputs must confirm immediately"
-        );
-        first.set_read_timeout(Some(Duration::from_secs(1))).unwrap();
-        let mut event = [0u8; 8];
-        first.read_exact(&mut event).unwrap();
-        assert_eq!(u32::from_ne_bytes(event[..4].try_into().unwrap()), 2);
-        assert_eq!(
-            u32::from_ne_bytes(event[4..].try_into().unwrap()),
-            8u32 << 16,
-            "protocol locked event"
-        );
-
-        let owner = state.session_lock.lifecycle.owner().cloned();
-
-        let mut competitor = acquire(&mut state);
-        dispatch(&mut event_loop, &mut state);
-        assert_eq!(
-            state.session_lock.lifecycle.owner(),
-            owner.as_ref(),
-            "a live owner cannot be replaced"
-        );
-        // A rejected client must not unlock the confirmed owner.
-        for word in [2u32, (8u32 << 16) | 2] {
-            competitor.write_all(&word.to_ne_bytes()).unwrap();
-        }
-        dispatch(&mut event_loop, &mut state);
-        assert_eq!(state.session_lock.lifecycle.owner(), owner.as_ref());
-
-        drop(competitor);
-        drop(first);
-        dispatch(&mut event_loop, &mut state);
-        assert!(matches!(state.session_lock.lifecycle, Lifecycle::Orphaned));
-        assert!(state.session_lock.active());
-
-        let replacement = acquire(&mut state);
-        dispatch(&mut event_loop, &mut state);
-        assert!(matches!(state.session_lock.lifecycle, Lifecycle::Locked(_)));
-        assert_ne!(state.session_lock.lifecycle.owner(), owner.as_ref());
-        drop(replacement);
-        dispatch(&mut event_loop, &mut state);
-        assert!(state.session_lock.active());
-
-        let output = Output::new(
-            "last-output".into(),
-            smithay::output::PhysicalProperties {
-                size: (0, 0).into(),
-                subpixel: smithay::output::Subpixel::Unknown,
-                make: "test".into(),
-                model: "test".into(),
-            },
-        );
-        output.change_current_state(
-            Some(smithay::output::Mode {
-                size: (800, 600).into(),
-                refresh: 60_000,
-            }),
-            None,
-            None,
-            None,
-        );
-        state.space.map_output(&output, (0, 0));
-        state.register_output(&output, "last-output".into());
-
-        let pending = acquire(&mut state);
-        dispatch(&mut event_loop, &mut state);
-        assert!(
-            matches!(state.session_lock.lifecycle, Lifecycle::Acquiring(_)),
-            "a newly added output requires a protected frame"
-        );
-        drop(pending);
-        dispatch(&mut event_loop, &mut state);
-        assert!(matches!(state.session_lock.lifecycle, Lifecycle::Orphaned));
-
-        let replacement = acquire(&mut state);
-        dispatch(&mut event_loop, &mut state);
-        assert!(matches!(state.session_lock.lifecycle, Lifecycle::Acquiring(_)));
-        state.unregister_output(&output);
-        assert!(
-            matches!(state.session_lock.lifecycle, Lifecycle::Locked(_)),
-            "removing the last pending output must confirm"
-        );
-
-        drop(replacement);
-        dispatch(&mut event_loop, &mut state);
-        state.space.map_output(&output, (0, 0));
-        state.session_lock.output_added(&output);
-
-        let mut pending = acquire(&mut state);
-        dispatch(&mut event_loop, &mut state);
-        assert!(matches!(state.session_lock.lifecycle, Lifecycle::Acquiring(_)));
-        assert!(state.session_lock.idle_timer.is_none());
-
-        // Remove the final display without delivering a frame or confirming during removal.
-        state.space.unmap_output(&output);
-        state.session_lock.output_removed(&output);
-        assert!(matches!(state.session_lock.lifecycle, Lifecycle::Acquiring(_)));
-
-        state.refresh_lock_outputs();
-        assert!(matches!(state.session_lock.lifecycle, Lifecycle::Locked(_)));
-        assert!(state.session_lock.idle_timer.is_some());
-        state.display_handle.flush_clients().unwrap();
-        pending.set_read_timeout(Some(Duration::from_secs(1))).unwrap();
-        pending.read_exact(&mut event).unwrap();
-        assert_eq!(u32::from_ne_bytes(event[..4].try_into().unwrap()), 2);
-        assert_eq!(u32::from_ne_bytes(event[4..].try_into().unwrap()), 8u32 << 16);
-    }
-
-    #[test]
-    fn dim_fade_respects_speed_without_changing_idle_deadlines() {
-        let policy = IdleSettings::default();
-        for (duration, half_at) in [(250, 30_125), (1000, 30_500)] {
-            let fade = Duration::from_millis(duration);
-            assert_eq!(policy.appearance(Duration::from_secs(29), fade), (0.0, false));
-            let halfway = policy.appearance(Duration::from_millis(half_at), fade);
-            assert!((halfway.0 - 0.325).abs() < 0.001 && !halfway.1);
-            assert_eq!(
-                policy.next_deadline(Duration::from_millis(half_at), fade),
-                Some(Duration::from_millis(16))
-            );
-            assert_eq!(policy.appearance(Duration::from_secs(120), fade), (1.0, true));
-        }
-        assert_eq!(
-            policy.appearance(Duration::from_secs(30), Duration::ZERO),
-            (0.65, false)
-        );
-        assert_eq!(policy.appearance(Duration::from_secs(120), Duration::ZERO), (1.0, true));
-    }
-
-    #[test]
-    fn idle_policy_fades_then_sleeps_and_activity_resets_it() {
-        let policy = IdleSettings::default();
-        assert_eq!(
-            policy.appearance(Duration::from_secs(29), Duration::from_millis(500)),
-            (0.0, false)
-        );
-        let halfway = policy.appearance(Duration::from_millis(30_250), Duration::from_millis(500));
-        assert!((halfway.0 - 0.325).abs() < 0.001 && !halfway.1);
-        assert_eq!(
-            policy.appearance(Duration::from_secs(31), Duration::from_millis(500)),
-            (0.65, false)
-        );
-        assert_eq!(
-            policy.appearance(Duration::from_secs(120), Duration::from_millis(500)),
-            (1.0, true)
-        );
-        assert_eq!(
-            policy.appearance(Duration::ZERO, Duration::from_millis(500)),
-            (0.0, false)
-        );
-        assert_eq!(
-            policy.next_deadline(Duration::from_millis(29_998), Duration::from_millis(500)),
-            Some(Duration::from_millis(2))
-        );
-        assert_eq!(
-            policy.next_deadline(Duration::from_secs(30), Duration::from_millis(500)),
-            Some(Duration::from_millis(16))
-        );
-        assert_eq!(
-            policy.next_deadline(Duration::from_secs(30), Duration::ZERO),
-            Some(Duration::from_secs(90))
-        );
-        assert_eq!(policy.next_deadline(Duration::from_secs(120), Duration::ZERO), None);
-        assert_eq!(
-            IdleSettings {
-                dim_after_seconds: 0,
-                sleep_after_seconds: 0
-            }
-            .next_deadline(Duration::ZERO, Duration::ZERO),
-            None
-        );
-    }
-
-    #[test]
-    fn mirror_must_present_protected_frame_before_lock_is_ready() {
-        let make_output = |name: &str| {
-            Output::new(
-                name.into(),
-                smithay::output::PhysicalProperties {
-                    size: (0, 0).into(),
-                    subpixel: smithay::output::Subpixel::Unknown,
-                    make: "test".into(),
-                    model: "test".into(),
-                },
-            )
-        };
-        let source = make_output("source");
-        let mirror = make_output("mirror");
-        let mut lock = Lock {
-            lifecycle: Lifecycle::Orphaned,
-            ..Lock::default()
-        };
-        lock.presented.insert(source.clone());
-        let displays = [&source, &mirror];
-        assert!(
-            !lock.ready_for_idle(displays.into_iter()),
-            "failed mirror rendering must block confirmation"
-        );
-        lock.presented.insert(mirror.clone());
-        assert!(lock.ready_for_idle(displays.into_iter()));
-        lock.output_added(&mirror);
-        assert!(
-            !lock.ready_for_idle(displays.into_iter()),
-            "reconfiguration invalidates physical protection"
-        );
-        lock.output_removed(&mirror);
-        assert!(lock.ready_for_idle(std::iter::once(&source)));
-    }
-
-    #[test]
-    fn protected_fallback_frames_allow_idle_after_early_locker_crash() {
-        let output = Output::new(
-            "test".into(),
-            smithay::output::PhysicalProperties {
-                size: (0, 0).into(),
-                subpixel: smithay::output::Subpixel::Unknown,
-                make: "test".into(),
-                model: "test".into(),
-            },
-        );
-        let mut lock = Lock {
-            lifecycle: Lifecycle::Orphaned,
-            ..Lock::default()
-        };
-        assert!(!lock.ready_for_idle(std::iter::once(&output)));
-        lock.presented.insert(output.clone());
-        assert!(lock.ready_for_idle(std::iter::once(&output)));
-        assert!(matches!(lock.lifecycle, Lifecycle::Orphaned));
-        lock.output_added(&output);
-        assert!(!lock.ready_for_idle(std::iter::once(&output)));
-        assert!(matches!(lock.lifecycle, Lifecycle::Orphaned));
-    }
-
-    #[test]
-    fn input_wakes_a_sleeping_orphan_without_unlocking() {
-        let mut lock = Lock {
-            lifecycle: Lifecycle::Orphaned,
-            sleeping: true,
-            idle_opacity: 1.0,
-            ..Lock::default()
-        };
-        let now = Instant::now();
-        assert!(lock.activity(now));
-        assert!(lock.active() && matches!(lock.lifecycle, Lifecycle::Orphaned));
-        assert!(!lock.sleeping);
-        assert_eq!(lock.idle_opacity, 0.0);
-        assert_eq!(lock.idle_since, Some(now));
-        assert!(!lock.activity(now));
-        let mut unlocked = Lock::default();
-        assert!(!unlocked.activity(now));
-        assert!(unlocked.idle_since.is_none());
-    }
-
-    #[test]
-    fn idle_disabled_options_are_independent() {
-        assert_eq!(
-            IdleSettings {
-                dim_after_seconds: 0,
-                sleep_after_seconds: 0
-            }
-            .appearance(Duration::from_secs(9999), Duration::from_millis(500)),
-            (0.0, false)
-        );
-        assert_eq!(
-            IdleSettings {
-                dim_after_seconds: 0,
-                sleep_after_seconds: 10
-            }
-            .appearance(Duration::from_secs(10), Duration::from_millis(500)),
-            (1.0, true)
-        );
-        assert_eq!(
-            IdleSettings {
-                dim_after_seconds: 1,
-                sleep_after_seconds: 0
-            }
-            .appearance(Duration::from_secs(9999), Duration::from_millis(500)),
-            (0.65, false)
-        );
-        assert!(
-            IdleSettings {
-                dim_after_seconds: 86401,
-                sleep_after_seconds: 0
-            }
-            .validate()
-            .is_err()
-        );
-        assert!(crate::config::Config::parse_source("lock-screen { dim-after-seconds -1; }").is_err());
-        assert!(
-            crate::config::Config::parse_source("lock-screen { sleep-after-seconds 90000; }")
-                .unwrap()
-                .runtime_config()
-                .is_err()
-        );
-    }
-}
+mod tests;

compositor/src/session_lock/tests.rs

@@ -0,0 +1,628 @@
+use super::*;
+
+#[test]
+fn dim_fade_respects_speed_without_changing_idle_deadlines() {
+    let policy = IdleSettings::default();
+    for (duration, half_at) in [(250, 30_125), (1000, 30_500)] {
+        let fade = Duration::from_millis(duration);
+        assert_eq!(policy.appearance(Duration::from_secs(29), fade), (0.0, false));
+        let halfway = policy.appearance(Duration::from_millis(half_at), fade);
+        assert!((halfway.0 - 0.325).abs() < 0.001 && !halfway.1);
+        assert_eq!(
+            policy.next_deadline(Duration::from_millis(half_at), fade),
+            Some(Duration::from_millis(16))
+        );
+        assert_eq!(policy.appearance(Duration::from_secs(120), fade), (1.0, true));
+    }
+    assert_eq!(
+        policy.appearance(Duration::from_secs(30), Duration::ZERO),
+        (0.65, false)
+    );
+    assert_eq!(policy.appearance(Duration::from_secs(120), Duration::ZERO), (1.0, true));
+}
+
+#[test]
+fn idle_policy_fades_then_sleeps_and_activity_resets_it() {
+    let policy = IdleSettings::default();
+    assert_eq!(
+        policy.appearance(Duration::from_secs(29), Duration::from_millis(500)),
+        (0.0, false)
+    );
+    let halfway = policy.appearance(Duration::from_millis(30_250), Duration::from_millis(500));
+    assert!((halfway.0 - 0.325).abs() < 0.001 && !halfway.1);
+    assert_eq!(
+        policy.appearance(Duration::from_secs(31), Duration::from_millis(500)),
+        (0.65, false)
+    );
+    assert_eq!(
+        policy.appearance(Duration::from_secs(120), Duration::from_millis(500)),
+        (1.0, true)
+    );
+    assert_eq!(
+        policy.appearance(Duration::ZERO, Duration::from_millis(500)),
+        (0.0, false)
+    );
+    assert_eq!(
+        policy.next_deadline(Duration::from_millis(29_998), Duration::from_millis(500)),
+        Some(Duration::from_millis(2))
+    );
+    assert_eq!(
+        policy.next_deadline(Duration::from_secs(30), Duration::from_millis(500)),
+        Some(Duration::from_millis(16))
+    );
+    assert_eq!(
+        policy.next_deadline(Duration::from_secs(30), Duration::ZERO),
+        Some(Duration::from_secs(90))
+    );
+    assert_eq!(policy.next_deadline(Duration::from_secs(120), Duration::ZERO), None);
+    assert_eq!(
+        IdleSettings {
+            dim_after_seconds: 0,
+            sleep_after_seconds: 0
+        }
+        .next_deadline(Duration::ZERO, Duration::ZERO),
+        None
+    );
+}
+
+#[test]
+fn mirror_must_present_protected_frame_before_lock_is_ready() {
+    let make_output = |name: &str| {
+        Output::new(
+            name.into(),
+            smithay::output::PhysicalProperties {
+                size: (0, 0).into(),
+                subpixel: smithay::output::Subpixel::Unknown,
+                make: "test".into(),
+                model: "test".into(),
+            },
+        )
+    };
+    let source = make_output("source");
+    let mirror = make_output("mirror");
+    let mut lock = Lock {
+        lifecycle: Lifecycle::Orphaned,
+        ..Lock::default()
+    };
+    lock.presented.insert(source.clone());
+    let displays = [&source, &mirror];
+    assert!(
+        !lock.ready_for_idle(displays.into_iter()),
+        "failed mirror rendering must block confirmation"
+    );
+    lock.presented.insert(mirror.clone());
+    assert!(lock.ready_for_idle(displays.into_iter()));
+    lock.output_added(&mirror);
+    assert!(
+        !lock.ready_for_idle(displays.into_iter()),
+        "reconfiguration invalidates physical protection"
+    );
+    lock.output_removed(&mirror);
+    assert!(lock.ready_for_idle(std::iter::once(&source)));
+}
+
+#[test]
+fn protected_fallback_frames_allow_idle_after_early_locker_crash() {
+    let output = Output::new(
+        "test".into(),
+        smithay::output::PhysicalProperties {
+            size: (0, 0).into(),
+            subpixel: smithay::output::Subpixel::Unknown,
+            make: "test".into(),
+            model: "test".into(),
+        },
+    );
+    let mut lock = Lock {
+        lifecycle: Lifecycle::Orphaned,
+        ..Lock::default()
+    };
+    assert!(!lock.ready_for_idle(std::iter::once(&output)));
+    lock.presented.insert(output.clone());
+    assert!(lock.ready_for_idle(std::iter::once(&output)));
+    assert!(matches!(lock.lifecycle, Lifecycle::Orphaned));
+    lock.output_added(&output);
+    assert!(!lock.ready_for_idle(std::iter::once(&output)));
+    assert!(matches!(lock.lifecycle, Lifecycle::Orphaned));
+}
+
+#[test]
+fn input_wakes_a_sleeping_orphan_without_unlocking() {
+    let mut lock = Lock {
+        lifecycle: Lifecycle::Orphaned,
+        sleeping: true,
+        idle_opacity: 1.0,
+        ..Lock::default()
+    };
+    let now = Instant::now();
+    assert!(lock.activity(now));
+    assert!(lock.active() && matches!(lock.lifecycle, Lifecycle::Orphaned));
+    assert!(!lock.sleeping);
+    assert_eq!(lock.idle_opacity, 0.0);
+    assert_eq!(lock.idle_since, Some(now));
+    assert!(!lock.activity(now));
+    let mut unlocked = Lock::default();
+    assert!(!unlocked.activity(now));
+    assert!(unlocked.idle_since.is_none());
+}
+
+#[test]
+fn idle_disabled_options_are_independent() {
+    assert_eq!(
+        IdleSettings {
+            dim_after_seconds: 0,
+            sleep_after_seconds: 0
+        }
+        .appearance(Duration::from_secs(9999), Duration::from_millis(500)),
+        (0.0, false)
+    );
+    assert_eq!(
+        IdleSettings {
+            dim_after_seconds: 0,
+            sleep_after_seconds: 10
+        }
+        .appearance(Duration::from_secs(10), Duration::from_millis(500)),
+        (1.0, true)
+    );
+    assert_eq!(
+        IdleSettings {
+            dim_after_seconds: 1,
+            sleep_after_seconds: 0
+        }
+        .appearance(Duration::from_secs(9999), Duration::from_millis(500)),
+        (0.65, false)
+    );
+    assert!(
+        IdleSettings {
+            dim_after_seconds: 86401,
+            sleep_after_seconds: 0
+        }
+        .validate()
+        .is_err()
+    );
+    assert!(crate::config::Config::parse_source("lock-screen { dim-after-seconds -1; }").is_err());
+    assert!(
+        crate::config::Config::parse_source("lock-screen { sleep-after-seconds 90000; }")
+            .unwrap()
+            .runtime_config()
+            .is_err()
+    );
+}
+
+use std::io::{Read, Write};
+use std::os::unix::net::UnixStream;
+use std::sync::Arc;
+
+use calloop::EventLoop;
+use smithay::reexports::wayland_server::Client;
+use smithay::reexports::wayland_server::protocol::wl_compositor::WlCompositor;
+
+struct Fixture {
+    events: EventLoop<'static, Ferese>,
+    state: Ferese,
+}
+
+impl Fixture {
+    fn new(test: &str) -> Option<Self> {
+        if !crate::startup_tests::private_runtime(test) {
+            return None;
+        }
+
+        let mut events = EventLoop::try_new().unwrap();
+        let state = crate::startup_tests::state(&mut events);
+        Some(Self { events, state })
+    }
+
+    fn dispatch(&mut self) {
+        self.events.dispatch(Duration::from_millis(5), &mut self.state).unwrap();
+        crate::after_dispatch(&mut self.state);
+    }
+
+    fn output(&mut self, name: &str) -> Output {
+        let output = Output::new(
+            name.into(),
+            smithay::output::PhysicalProperties {
+                size: (0, 0).into(),
+                subpixel: smithay::output::Subpixel::Unknown,
+                make: "test".into(),
+                model: "test".into(),
+            },
+        );
+        output.change_current_state(
+            Some(smithay::output::Mode {
+                size: (800, 600).into(),
+                refresh: 60_000,
+            }),
+            None,
+            None,
+            None,
+        );
+        self.state.space.map_output(&output, (0, 0));
+        self.state.register_output(&output, name.into());
+        output
+    }
+
+    fn acquire(&mut self) -> Locker {
+        let (server, mut wire) = UnixStream::pair().unwrap();
+        let client = self
+            .state
+            .display_handle
+            .insert_client(server, Arc::new(crate::state::ClientState::default()))
+            .unwrap();
+        let manager = client
+            .create_resource::<ExtSessionLockManagerV1, (), Ferese>(&self.state.display_handle, 1, ())
+            .unwrap();
+        request(&mut wire, manager.id().protocol_id(), 1, &[2]);
+        self.dispatch();
+        Locker {
+            wire,
+            client,
+            next_id: 3,
+        }
+    }
+}
+
+struct Locker {
+    wire: UnixStream,
+    client: Client,
+    next_id: u32,
+}
+
+impl Locker {
+    fn id(&mut self) -> u32 {
+        let id = self.next_id;
+        self.next_id += 1;
+        id
+    }
+
+    fn expect_locked(&mut self) {
+        self.wire.set_read_timeout(Some(Duration::from_secs(1))).unwrap();
+        let mut event = [0u8; 8];
+        self.wire.read_exact(&mut event).unwrap();
+        assert_eq!(u32::from_ne_bytes(event[..4].try_into().unwrap()), 2);
+        assert_eq!(u32::from_ne_bytes(event[4..].try_into().unwrap()), 8u32 << 16);
+    }
+
+    fn surface(&mut self, fixture: &mut Fixture, output: &Output) -> LockSurface {
+        output.create_global::<Ferese>(&fixture.state.display_handle);
+        let registry = self.id();
+        request(&mut self.wire, 1, 1, &[registry]);
+        fixture.dispatch();
+        self.wire.set_nonblocking(true).unwrap();
+        let mut events = Vec::new();
+        let _ = self.wire.read_to_end(&mut events);
+        self.wire.set_nonblocking(false).unwrap();
+        let mut offset = 0;
+        let mut output_name = None;
+        while offset < events.len() {
+            let object = u32::from_ne_bytes(events[offset..offset + 4].try_into().unwrap());
+            let header = u32::from_ne_bytes(events[offset + 4..offset + 8].try_into().unwrap());
+            if object == registry && header & 0xffff == 0 {
+                let len = u32::from_ne_bytes(events[offset + 12..offset + 16].try_into().unwrap()) as usize;
+                if &events[offset + 16..offset + 16 + len] == b"wl_output\0" {
+                    let name = u32::from_ne_bytes(events[offset + 8..offset + 12].try_into().unwrap());
+                    output_name = Some(output_name.map_or(name, |previous: u32| previous.max(name)));
+                }
+            }
+
+            offset += (header >> 16) as usize;
+        }
+
+        let output_id = self.id();
+        let mut args = vec![output_name.expect("output global"), 10];
+        args.extend(
+            b"wl_output\0\0\0"
+                .chunks_exact(4)
+                .map(|bytes| u32::from_ne_bytes(bytes.try_into().unwrap())),
+        );
+        args.extend([4, output_id]);
+        request(&mut self.wire, registry, 0, &args);
+        let compositor = self
+            .client
+            .create_resource::<WlCompositor, (), Ferese>(&fixture.state.display_handle, 6, ())
+            .unwrap();
+        let surface_id = self.id();
+        request(&mut self.wire, compositor.id().protocol_id(), 0, &[surface_id]);
+        let lock_surface = self.id();
+        request(&mut self.wire, 2, 1, &[lock_surface, surface_id, output_id]);
+        fixture.dispatch();
+        fixture
+            .state
+            .session_lock
+            .surfaces
+            .get(output)
+            .expect("lock surface on requested output")
+            .clone()
+    }
+}
+
+fn request(wire: &mut UnixStream, object: u32, opcode: u32, args: &[u32]) {
+    for word in [object, (((args.len() + 2) * 4) as u32) << 16 | opcode]
+        .into_iter()
+        .chain(args.iter().copied())
+    {
+        wire.write_all(&word.to_ne_bytes()).unwrap();
+    }
+}
+
+#[test]
+fn lock_confirms_without_outputs() {
+    let Some(mut fixture) = Fixture::new("session_lock::tests::lock_confirms_without_outputs") else {
+        return;
+    };
+    let epoch = fixture.state.capture_epoch;
+    let mut locker = fixture.acquire();
+    assert!(matches!(fixture.state.session_lock.lifecycle, Lifecycle::Locked(_)));
+    assert_ne!(fixture.state.capture_epoch, epoch, "lock revokes deferred snapshots");
+    locker.expect_locked();
+}
+
+#[test]
+fn lock_waits_for_each_output_before_confirmation() {
+    let Some(mut fixture) = Fixture::new("session_lock::tests::lock_waits_for_each_output_before_confirmation") else {
+        return;
+    };
+    let first = fixture.output("first");
+    let second = fixture.output("second");
+    let mut locker = fixture.acquire();
+    assert!(matches!(fixture.state.session_lock.lifecycle, Lifecycle::Acquiring(_)));
+    fixture.state.lock_frame_presented(&first);
+    assert!(matches!(fixture.state.session_lock.lifecycle, Lifecycle::Acquiring(_)));
+    assert!(fixture.state.session_lock.idle_timer.is_none());
+    fixture.state.lock_frame_presented(&second);
+    assert!(matches!(fixture.state.session_lock.lifecycle, Lifecycle::Locked(_)));
+    fixture.dispatch();
+    locker.expect_locked();
+}
+
+#[test]
+fn live_owner_rejects_competitor_unlock() {
+    let Some(mut fixture) = Fixture::new("session_lock::tests::live_owner_rejects_competitor_unlock") else {
+        return;
+    };
+    let _owner_wire = fixture.acquire();
+    let owner = fixture.state.session_lock.lifecycle.owner().cloned();
+    let mut competitor = fixture.acquire();
+    assert_eq!(fixture.state.session_lock.lifecycle.owner(), owner.as_ref());
+    request(&mut competitor.wire, 2, 2, &[]);
+    fixture.dispatch();
+    assert_eq!(fixture.state.session_lock.lifecycle.owner(), owner.as_ref());
+    assert!(fixture.state.session_lock.active());
+}
+
+#[test]
+fn pending_owner_cannot_unlock_before_confirmation() {
+    let Some(mut fixture) = Fixture::new("session_lock::tests::pending_owner_cannot_unlock_before_confirmation") else {
+        return;
+    };
+    fixture.output("pending");
+    let mut pending = fixture.acquire();
+    assert!(matches!(fixture.state.session_lock.lifecycle, Lifecycle::Acquiring(_)));
+    request(&mut pending.wire, 2, 2, &[]);
+    fixture.dispatch();
+    assert!(fixture.state.session_lock.active());
+    fixture.dispatch();
+    assert!(matches!(fixture.state.session_lock.lifecycle, Lifecycle::Orphaned));
+}
+
+#[test]
+fn owner_disconnect_stays_locked_and_allows_replacement() {
+    let Some(mut fixture) = Fixture::new("session_lock::tests::owner_disconnect_stays_locked_and_allows_replacement")
+    else {
+        return;
+    };
+    let owner_wire = fixture.acquire();
+    let owner = fixture.state.session_lock.lifecycle.owner().cloned();
+    drop(owner_wire);
+    fixture.dispatch();
+    assert!(matches!(fixture.state.session_lock.lifecycle, Lifecycle::Orphaned));
+    assert!(fixture.state.session_lock.active());
+    let mut replacement = fixture.acquire();
+    assert!(matches!(fixture.state.session_lock.lifecycle, Lifecycle::Locked(_)));
+    assert_ne!(fixture.state.session_lock.lifecycle.owner(), owner.as_ref());
+    replacement.expect_locked();
+}
+
+#[test]
+fn removing_last_output_confirms_pending_lock() {
+    let Some(mut fixture) = Fixture::new("session_lock::tests::removing_last_output_confirms_pending_lock") else {
+        return;
+    };
+    let output = fixture.output("last");
+    let mut pending = fixture.acquire();
+    assert!(matches!(fixture.state.session_lock.lifecycle, Lifecycle::Acquiring(_)));
+    fixture.state.unregister_output(&output);
+    assert!(matches!(fixture.state.session_lock.lifecycle, Lifecycle::Locked(_)));
+    fixture.dispatch();
+    pending.expect_locked();
+}
+
+#[test]
+fn refresh_after_removal_confirms_and_starts_idle_timer() {
+    let Some(mut fixture) = Fixture::new("session_lock::tests::refresh_after_removal_confirms_and_starts_idle_timer")
+    else {
+        return;
+    };
+    let output = fixture.output("last");
+    let mut pending = fixture.acquire();
+    fixture.state.space.unmap_output(&output);
+    fixture.state.session_lock.output_removed(&output);
+    assert!(matches!(fixture.state.session_lock.lifecycle, Lifecycle::Acquiring(_)));
+    fixture.state.refresh_lock_outputs();
+    assert!(matches!(fixture.state.session_lock.lifecycle, Lifecycle::Locked(_)));
+    assert!(fixture.state.session_lock.idle_timer.is_some());
+    fixture.dispatch();
+    pending.expect_locked();
+}
+
+#[test]
+fn activity_reuses_timer_and_expired_timer_rechecks_latest_activity() {
+    let Some(mut fixture) =
+        Fixture::new("session_lock::tests::activity_reuses_timer_and_expired_timer_rechecks_latest_activity")
+    else {
+        return;
+    };
+    fixture.state.session_lock.lifecycle = Lifecycle::Orphaned;
+    fixture.state.lock_idle = IdleSettings {
+        dim_after_seconds: 1,
+        sleep_after_seconds: 2,
+    };
+    fixture.state.session_lock.idle_since = Some(Instant::now() - Duration::from_millis(999));
+    fixture.state.refresh_lock_idle_policy();
+    let timer = fixture.state.session_lock.idle_timer.unwrap();
+    for _ in 0..1000 {
+        fixture.state.lock_input_activity();
+        assert_eq!(
+            fixture.state.session_lock.idle_timer,
+            Some(timer),
+            "input replaced the source"
+        );
+    }
+
+    let limit = Instant::now() + Duration::from_secs(1);
+    while fixture.state.session_lock.idle_timer.unwrap().1 == timer.1 {
+        assert!(Instant::now() < limit, "idle timer did not recheck");
+        fixture
+            .events
+            .dispatch(Duration::from_millis(10), &mut fixture.state)
+            .unwrap();
+    }
+
+    let rechecked = fixture.state.session_lock.idle_timer.unwrap();
+    assert_eq!(timer.0, rechecked.0, "timer callback replaced the source");
+    assert!(rechecked.1 > timer.1);
+    assert_eq!(fixture.state.session_lock.idle_opacity, 0.0);
+    assert!(!fixture.state.session_lock.sleeping);
+}
+
+#[test]
+fn earlier_policy_replaces_timer_and_sleeping_activity_arms_one() {
+    let Some(mut fixture) =
+        Fixture::new("session_lock::tests::earlier_policy_replaces_timer_and_sleeping_activity_arms_one")
+    else {
+        return;
+    };
+    fixture.state.session_lock.lifecycle = Lifecycle::Orphaned;
+    fixture.state.lock_input_activity();
+    let first = fixture.state.session_lock.idle_timer.unwrap();
+    fixture.state.lock_idle.dim_after_seconds = 60;
+    fixture.state.refresh_lock_idle_policy();
+    assert_eq!(fixture.state.session_lock.idle_timer, Some(first));
+    fixture.state.lock_idle.dim_after_seconds = 1;
+    fixture.state.refresh_lock_idle_policy();
+    let earlier = fixture.state.session_lock.idle_timer.unwrap();
+    assert_ne!(first.0, earlier.0);
+    assert!(earlier.1 < first.1);
+    fixture.state.session_lock.idle_since = Some(Instant::now() - Duration::from_secs(121));
+    fixture.state.refresh_lock_idle_policy();
+    assert!(fixture.state.session_lock.sleeping);
+    assert!(fixture.state.session_lock.idle_timer.is_none());
+    fixture.state.lock_input_activity();
+    assert!(fixture.state.session_lock.idle_timer.is_some());
+    assert!(!fixture.state.session_lock.sleeping);
+    assert_eq!(fixture.state.session_lock.idle_opacity, 0.0);
+    assert!(fixture.state.session_lock.active());
+}
+
+#[test]
+fn dead_preferred_surface_uses_live_fallback_in_stable_output_order() {
+    let Some(mut fixture) =
+        Fixture::new("session_lock::tests::dead_preferred_surface_uses_live_fallback_in_stable_output_order")
+    else {
+        return;
+    };
+    let preferred = fixture.output("preferred");
+    let second = fixture.output("second");
+    let third = fixture.output("third");
+    let mut locker = fixture.acquire();
+    let dead = locker.surface(&mut fixture, &preferred);
+    let fallback = locker.surface(&mut fixture, &second);
+    let later = locker.surface(&mut fixture, &third);
+    let preferred_id = fixture.state.output_id(&preferred).unwrap();
+    fixture.state.output_workspaces.focus_output(preferred_id).unwrap();
+    request(&mut locker.wire, dead.wl_surface().id().protocol_id(), 0, &[]);
+    fixture.dispatch();
+    assert!(!dead.alive());
+    // Exercise the defensive path even though destruction normally removes it.
+    fixture.state.session_lock.surfaces.insert(preferred.clone(), dead);
+    for _ in 0..5 {
+        fixture.state.session_lock.surfaces.remove(&second);
+        fixture
+            .state
+            .session_lock
+            .surfaces
+            .insert(second.clone(), fallback.clone());
+        fixture.state.session_lock.surfaces.insert(third.clone(), later.clone());
+        fixture.state.focus_lock_surface();
+        assert_eq!(
+            fixture.state.seat.get_keyboard().unwrap().current_focus(),
+            Some(fallback.wl_surface().clone())
+        );
+    }
+}
+
+#[test]
+fn output_removed_clears_all_lock_resources() {
+    let Some(mut fixture) = Fixture::new("session_lock::tests::output_removed_clears_all_lock_resources") else {
+        return;
+    };
+    let output = fixture.output("removed");
+    let mut locker = fixture.acquire();
+    locker.surface(&mut fixture, &output);
+    let background =
+        smithay::backend::renderer::element::solid::SolidColorBuffer::new((800, 600), [0.0, 0.0, 0.0, 1.0]);
+    fixture
+        .state
+        .session_lock
+        .backgrounds
+        .insert(output.clone(), background.clone());
+    fixture
+        .state
+        .session_lock
+        .idle_overlays
+        .insert(output.clone(), background);
+    fixture.state.session_lock.presented.insert(output.clone());
+    fixture.state.session_lock.output_removed(&output);
+    let lock = &fixture.state.session_lock;
+    assert!(!lock.surfaces.contains_key(&output));
+    assert!(!lock.backgrounds.contains_key(&output));
+    assert!(!lock.idle_overlays.contains_key(&output));
+    assert!(!lock.presented.contains(&output));
+    assert!(lock.active(), "output cleanup must not unlock");
+}
+
+#[test]
+fn confirmed_owner_can_unlock_and_cancel_idle_timer() {
+    let Some(mut fixture) = Fixture::new("session_lock::tests::confirmed_owner_can_unlock_and_cancel_idle_timer")
+    else {
+        return;
+    };
+    let mut locker = fixture.acquire();
+    locker.expect_locked();
+    assert!(fixture.state.session_lock.idle_timer.is_some());
+    request(&mut locker.wire, 2, 2, &[]);
+    fixture.dispatch();
+    assert!(matches!(fixture.state.session_lock.lifecycle, Lifecycle::Unlocked));
+    assert!(fixture.state.session_lock.idle_timer.is_none());
+}
+
+#[test]
+fn acquiring_owner_disconnect_keeps_lock_and_replacement_waits_for_frame() {
+    let Some(mut fixture) =
+        Fixture::new("session_lock::tests::acquiring_owner_disconnect_keeps_lock_and_replacement_waits_for_frame")
+    else {
+        return;
+    };
+    let output = fixture.output("pending");
+    let pending = fixture.acquire();
+    assert!(matches!(fixture.state.session_lock.lifecycle, Lifecycle::Acquiring(_)));
+    drop(pending);
+    fixture.dispatch();
+    assert!(matches!(fixture.state.session_lock.lifecycle, Lifecycle::Orphaned));
+    assert!(fixture.state.session_lock.active());
+    let mut replacement = fixture.acquire();
+    assert!(matches!(fixture.state.session_lock.lifecycle, Lifecycle::Acquiring(_)));
+    fixture.state.lock_frame_presented(&output);
+    fixture.dispatch();
+    assert!(matches!(fixture.state.session_lock.lifecycle, Lifecycle::Locked(_)));
+    replacement.expect_locked();
+}

compositor/src/startup_tests.rs

@@ -0,0 +1,253 @@
+use std::io::{Read, Write};
+use std::os::unix::net::UnixStream;
+use std::os::unix::process::ExitStatusExt;
+use std::process::{Command, Stdio};
+use std::sync::Arc;
+use std::time::{Duration, Instant};
+
+use calloop::EventLoop;
+use calloop::signals::{Signal, Signals};
+use smithay::input::SeatHandler;
+use smithay::input::pointer::{CursorImageStatus, MotionEvent};
+use smithay::reexports::wayland_server::protocol::{wl_compositor::WlCompositor, wl_surface::WlSurface};
+use smithay::reexports::wayland_server::{Display, Resource};
+use smithay::utils::SERIAL_COUNTER;
+
+use crate::{Ferese, RedrawRequest, after_dispatch, after_dispatch_with_redraw};
+
+// Each state needs its own sockets and environment. A subprocess also bounds
+// the cursor deadlock test without changing environment variables across tests.
+pub(crate) fn private_runtime(test: &str) -> bool {
+    const CHILD: &str = "FERESE_STARTUP_TEST_CHILD";
+    if std::env::var_os(CHILD).is_some_and(|value| value == test) {
+        return true;
+    }
+
+    let directory = tempfile::tempdir().unwrap();
+    let log_path = directory.path().join("test.log");
+    let log = std::fs::File::create(&log_path).unwrap();
+    let mut child = Command::new(std::env::current_exe().unwrap())
+        .args(["--exact", test, "--nocapture"])
+        .env(CHILD, test)
+        .env("XDG_RUNTIME_DIR", directory.path())
+        .env("XDG_CONFIG_HOME", directory.path())
+        .env("XDG_STATE_HOME", directory.path())
+        .env("XDG_CACHE_HOME", directory.path())
+        .env_remove("FERESE_SOCKET")
+        .stdout(Stdio::from(log.try_clone().unwrap()))
+        .stderr(Stdio::from(log))
+        .spawn()
+        .unwrap();
+    let deadline = Instant::now() + Duration::from_secs(20);
+    let status = loop {
+        if let Some(status) = child.try_wait().unwrap() {
+            break status;
+        }
+
+        if Instant::now() >= deadline {
+            child.kill().unwrap();
+            child.wait().unwrap();
+            panic!("{test} did not complete; possible startup deadlock");
+        }
+
+        std::thread::sleep(Duration::from_millis(10));
+    };
+
+    assert!(status.success(), "{}", std::fs::read_to_string(log_path).unwrap());
+    false
+}
+
+pub(crate) fn state(events: &mut EventLoop<'static, Ferese>) -> Ferese {
+    let mut config = crate::config::Config::default().runtime_config().unwrap();
+    config.wallpaper.path = None;
+
+    Ferese::new(events, Display::new().unwrap(), config).unwrap()
+}
+
+#[test]
+fn launched_clients_unblock_termination_signals_and_keep_private_sockets() {
+    if !private_runtime("startup_tests::launched_clients_unblock_termination_signals_and_keep_private_sockets") {
+        return;
+    }
+
+    let mut events = EventLoop::try_new().unwrap();
+    let mut state = state(&mut events);
+    let signals = Signals::new(&[Signal::SIGINT, Signal::SIGTERM, Signal::SIGUSR1]).unwrap();
+    let mut private = crate::private_client::ClientCapabilities::EFFECTS;
+    private.insert(crate::private_client::ClientCapabilities::SHELL_CONTROL);
+    for capabilities in [crate::private_client::ClientCapabilities::default(), private] {
+        let mut child = crate::process::spawn_client(&mut state, ["/bin/sleep", "30"], capabilities).unwrap();
+        let status = std::fs::read_to_string(format!("/proc/{}/status", child.id())).unwrap();
+        let blocked = status.lines().find(|line| line.starts_with("SigBlk:")).unwrap();
+        let blocked = u64::from_str_radix(blocked.split_whitespace().nth(1).unwrap(), 16).unwrap();
+        assert_eq!(blocked & ((1 << (libc::SIGINT - 1)) | (1 << (libc::SIGTERM - 1))), 0);
+        assert_ne!(blocked & (1 << (libc::SIGUSR1 - 1)), 0, "unrelated mask was lost");
+        if !capabilities.is_empty() {
+            let environment = std::fs::read(format!("/proc/{}/environ", child.id())).unwrap();
+            for name in ["WAYLAND_SOCKET=", "FERESE_SHELL_CONTROL_SOCKET="] {
+                let variable = environment
+                    .split(|byte| *byte == 0)
+                    .filter_map(|value| std::str::from_utf8(value).ok())
+                    .find_map(|value| value.strip_prefix(name))
+                    .unwrap();
+                let fd = std::fs::read_link(format!("/proc/{}/fd/{variable}", child.id())).unwrap();
+                assert!(fd.to_string_lossy().starts_with("socket:["));
+            }
+        }
+
+        crate::process::terminate_child(&mut child);
+        assert_eq!(
+            child.wait().unwrap().signal(),
+            Some(libc::SIGTERM),
+            "child needed SIGKILL"
+        );
+    }
+
+    // Child setup must not unblock the compositor's own signalfd mask.
+    let mut mask = unsafe { std::mem::zeroed() };
+    assert_eq!(
+        unsafe { libc::pthread_sigmask(libc::SIG_BLOCK, std::ptr::null(), &mut mask) },
+        0
+    );
+    assert_eq!(unsafe { libc::sigismember(&mask, libc::SIGINT) }, 1);
+    assert_eq!(unsafe { libc::sigismember(&mask, libc::SIGTERM) }, 1);
+    drop(signals);
+}
+
+#[test]
+fn explicit_client_exit_is_reaped_without_stopping_the_compositor() {
+    if !private_runtime("startup_tests::explicit_client_exit_is_reaped_without_stopping_the_compositor") {
+        return;
+    }
+
+    let mut events = EventLoop::try_new().unwrap();
+    let mut state = state(&mut events);
+    let child = crate::process::spawn_client(
+        &mut state,
+        ["/bin/sh", "-c", "exit 7"],
+        crate::private_client::ClientCapabilities::default(),
+    )
+    .unwrap();
+    let pid = child.id();
+    let watched = crate::process::watch_client_exit(&events.handle(), child);
+    let deadline = Instant::now() + Duration::from_secs(2);
+    while watched.borrow().is_some() {
+        assert!(Instant::now() < deadline, "client was not reaped");
+        events.dispatch(Duration::from_millis(10), &mut state).unwrap();
+        after_dispatch(&mut state);
+    }
+
+    let mut status = 0;
+    assert_eq!(unsafe { libc::waitpid(pid as i32, &mut status, libc::WNOHANG) }, -1);
+    assert_eq!(std::io::Error::last_os_error().raw_os_error(), Some(libc::ECHILD));
+    // Exit watching removes itself; subsequent event-loop dispatch remains usable.
+    events.dispatch(Duration::ZERO, &mut state).unwrap();
+}
+
+#[test]
+fn check_config_rejects_an_otherwise_valid_oversized_file() {
+    let directory = tempfile::tempdir().unwrap();
+    let path = directory.path().join("config.kdl");
+    let valid = format!("//{}\n", "x".repeat(60 * 1024 - 3));
+    std::fs::write(&path, &valid).unwrap();
+    crate::check_config(&path).unwrap();
+    assert!(crate::theme::prepare(&(valid.clone() + "\n"), directory.path()).is_ok());
+    std::fs::write(&path, valid + "\n").unwrap();
+    let error = crate::check_config(&path).unwrap_err();
+    assert!(error.contains("exceeds 60 KiB"), "{error}");
+    assert_eq!(crate::theme::read_source(&path).unwrap_err(), error);
+}
+
+#[test]
+fn deferred_cursor_redraw_runs_after_input_lock_is_released() {
+    if !private_runtime("startup_tests::deferred_cursor_redraw_runs_after_input_lock_is_released") {
+        return;
+    }
+
+    let mut events = EventLoop::try_new().unwrap();
+    let mut state = state(&mut events);
+    let (server, mut client_wire) = UnixStream::pair().unwrap();
+    let client = state
+        .display_handle
+        .insert_client(server, Arc::new(crate::state::ClientState::default()))
+        .unwrap();
+    let compositor = client
+        .create_resource::<WlCompositor, (), Ferese>(&state.display_handle, 6, ())
+        .unwrap();
+    // wl_compositor.create_surface(new_id=2).
+    for word in [compositor.id().protocol_id(), 12u32 << 16, 2] {
+        client_wire.write_all(&word.to_ne_bytes()).unwrap();
+    }
+
+    events.dispatch(Duration::from_millis(10), &mut state).unwrap();
+    let surface = client
+        .object_from_protocol_id::<WlSurface>(&state.display_handle, 2)
+        .unwrap();
+    let pointer = state.seat.get_pointer().unwrap();
+    let seat = state.seat.clone();
+    state.cursor_image(&seat, CursorImageStatus::Hidden);
+    after_dispatch_with_redraw(&mut state, |_, _| {});
+    events.handle().insert_idle(move |state| {
+        for _ in 0..2 {
+            let event = MotionEvent {
+                location: (10.0, 20.0).into(),
+                serial: SERIAL_COUNTER.next_serial(),
+                time: 0,
+            };
+            pointer.motion(state, Some((surface.clone(), (0.0, 0.0).into())), &event);
+            // Smithay invokes Ferese::cursor_image while holding its real pointer lock.
+            pointer.motion(state, None, &event);
+            assert!(state.cursor_redraw_pending);
+        }
+    });
+    let signal = events.get_signal();
+    let mut redraws = 0;
+    events
+        .run(Some(Duration::ZERO), &mut state, |state| {
+            after_dispatch_with_redraw(state, |state, request| {
+                assert!(matches!(request, RedrawRequest::Cursor));
+                assert_eq!(
+                    state.seat.get_pointer().unwrap().current_location(),
+                    (10.0, 20.0).into()
+                );
+                redraws += 1;
+            });
+            assert!(!state.cursor_redraw_pending);
+            signal.stop();
+        })
+        .unwrap();
+    assert_eq!(redraws, 1);
+    after_dispatch_with_redraw(&mut state, |_, _| panic!("redraw was not consumed"));
+}
+
+#[test]
+fn wayland_roundtrip_completes_without_a_rendered_frame() {
+    if !private_runtime("startup_tests::wayland_roundtrip_completes_without_a_rendered_frame") {
+        return;
+    }
+
+    let mut events = EventLoop::try_new().unwrap();
+    let mut state = state(&mut events);
+    let (server, mut client) = UnixStream::pair().unwrap();
+    state
+        .display_handle
+        .insert_client(server, Arc::new(crate::state::ClientState::default()))
+        .unwrap();
+    // wl_display.sync(new_id=2), using native-endian Wayland wire format.
+    for word in [1u32, 12u32 << 16, 2u32] {
+        client.write_all(&word.to_ne_bytes()).unwrap();
+    }
+
+    events.dispatch(Duration::from_millis(10), &mut state).unwrap();
+    client.set_read_timeout(Some(Duration::from_millis(20))).unwrap();
+    let mut reply = [0u8; 12];
+    assert!(
+        client.read_exact(&mut reply).is_err(),
+        "dispatch flushed replies before after_dispatch"
+    );
+    after_dispatch(&mut state);
+    client.set_read_timeout(Some(Duration::from_secs(1))).unwrap();
+    client.read_exact(&mut reply).unwrap();
+    assert_eq!(u32::from_ne_bytes(reply[0..4].try_into().unwrap()), 2);
+    assert_eq!(u32::from_ne_bytes(reply[4..8].try_into().unwrap()) & 0xffff, 0);
+}

compositor/src/state.rs

@@ -7,6 +7,8 @@ mod layout;
 mod navigation;
 mod outputs;
 mod reconciliation;
+#[cfg(test)]
+mod window_lifecycle_tests;
 pub(crate) use reconciliation::{DesktopChanges, DesktopOutput, DesktopTransition};
 mod prediction;
 mod presentation_dependencies;
@@ -478,6 +480,7 @@ pub struct Ferese {
     pub direct_backend: Option<DirectBackendState>,
     _ipc_socket: Option<IpcSocketGuard>,
     pending_dmabuf_imports: Vec<(Dmabuf, ImportNotifier)>,
+    pub(crate) activation_inputs: crate::handlers::activation::InputHistory,
     pub(crate) pending_screencopies: Vec<PendingScreencopy>,
     // Screenshot requests outlive the readback that filled them: the
     // coordinator owns them until encoding finishes and the caller is
@@ -721,6 +724,7 @@ impl Ferese {
             direct_backend: None,
             _ipc_socket: None,
             pending_dmabuf_imports: Vec::new(),
+            activation_inputs: Default::default(),
             pending_screencopies: Vec::new(),
             screenshot: Coordinator::new(),
             screenshot_parts: None,

compositor/src/state/capture_privacy.rs

@@ -138,4 +138,4 @@ impl Ferese {
 
 #[cfg(test)]
 #[path = "capture_privacy_tests.rs"]
-mod tests;
+pub(super) mod tests;

compositor/src/state/capture_privacy_tests.rs

@@ -22,7 +22,7 @@ use smithay::wayland::shell::xdg::{XdgShellHandler, XdgToplevelSurfaceData, XdgW
 use crate::Ferese;
 use crate::state::{ClientState, DesktopOutput};
 
-fn request(wire: &mut UnixStream, object: u32, opcode: u32, args: &[u32], fd: Option<RawFd>) {
+pub(crate) fn request(wire: &mut UnixStream, object: u32, opcode: u32, args: &[u32], fd: Option<RawFd>) {
     let bytes = [object, (((args.len() + 2) * 4) as u32) << 16 | opcode]
         .into_iter()
         .chain(args.iter().copied())
@@ -54,12 +54,12 @@ fn request(wire: &mut UnixStream, object: u32, opcode: u32, args: &[u32], fd: Op
     }
 }
 
-fn dispatch(events: &mut EventLoop<'static, Ferese>, state: &mut Ferese) {
+pub(crate) fn dispatch(events: &mut EventLoop<'static, Ferese>, state: &mut Ferese) {
     events.dispatch(Duration::from_millis(1), state).unwrap();
     state.display_handle.flush_clients().unwrap();
 }
 
-fn ack_configure(wire: &mut UnixStream, xdg: u32) -> u32 {
+pub(crate) fn ack_configure(wire: &mut UnixStream, xdg: u32) -> u32 {
     wire.set_nonblocking(true).unwrap();
     let mut bytes = Vec::new();
     let _ = wire.read_to_end(&mut bytes);
@@ -79,7 +79,7 @@ fn ack_configure(wire: &mut UnixStream, xdg: u32) -> u32 {
     serial.unwrap()
 }
 
-fn window(state: &mut Ferese, events: &mut EventLoop<'static, Ferese>, color: u32) -> (Window, UnixStream) {
+pub(crate) fn window(state: &mut Ferese, events: &mut EventLoop<'static, Ferese>, color: u32) -> (Window, UnixStream) {
     let (server, mut wire) = UnixStream::pair().unwrap();
     let client = state
         .display_handle
@@ -208,7 +208,7 @@ fn pixels(
                 Rectangle::from_size((320, 240).into()),
             ));
         let mut target = Some(texture.clone());
-        crate::backends::direct::capture::capture_output(state, renderer, &mut target, output, &scene).unwrap();
+        crate::backends::direct::capture::capture_output(state, renderer, &mut target, output, &scene);
         let mut result = receiver.try_recv().unwrap().result.unwrap().pixels;
         for pixel in result.chunks_exact_mut(4) {
             pixel.swap(0, 2);
@@ -424,8 +424,7 @@ fn capture_privacy_pixels_and_policy_transitions() {
         &mut Some(capture_texture.clone()),
         &output,
         &scene,
-    )
-    .unwrap();
+    );
     let region = receiver.try_recv().unwrap().result.unwrap();
     assert_eq!((region.width, region.height), (160, 120));
     assert!(

compositor/src/state/layout.rs

@@ -246,12 +246,14 @@ impl Ferese {
 
                 let is_maximized =
                     self.windows.record(*id).is_some_and(|w| w.maximized) && workspace_fullscreen != Some(*id);
+                let placement = self.workspaces.placement(*id);
+                let is_floating = matches!(placement, Some(WindowPlacement::Floating { .. }));
                 let rect = if workspace_fullscreen == Some(*id) {
                     fullscreen_bounds
-                } else if is_maximized && !is_scrolling_layout {
+                } else if is_maximized && (!is_scrolling_layout || is_floating) {
                     maximized_rect(bounds, self.gap_config.outer)
                 } else {
-                    match self.workspaces.placement(*id) {
+                    match placement {
                         Some(WindowPlacement::Tiled) => {
                             let Some(rect) = layout.geometry.get(id).copied() else {
                                 continue;
@@ -271,7 +273,6 @@ impl Ferese {
                 };
 
                 let is_fullscreen = workspace_fullscreen == Some(*id);
-                let is_floating = matches!(self.workspaces.placement(*id), Some(WindowPlacement::Floating { .. }));
 
                 visible.insert(*id);
                 let scrolling = if !is_fullscreen && !is_floating && (!is_maximized || is_scrolling_layout) {

compositor/src/state/outputs.rs

@@ -111,8 +111,6 @@ impl Ferese {
                 true
             }
         });
-        self.session_lock.surfaces.remove(output);
-        self.session_lock.backgrounds.remove(output);
         self.session_lock.output_removed(output);
     }
 

compositor/src/state/window_lifecycle_tests.rs

@@ -0,0 +1,281 @@
+use super::capture_privacy::tests::{ack_configure, dispatch, request, window};
+use super::*;
+use smithay::input::pointer::{Focus, GrabStartData, MotionEvent};
+use smithay::reexports::wayland_server::Resource;
+use smithay::utils::SERIAL_COUNTER;
+
+fn fixture() -> (smithay::reexports::calloop::EventLoop<'static, Ferese>, Ferese, Output) {
+    let mut events = smithay::reexports::calloop::EventLoop::try_new().unwrap();
+    let mut state = crate::startup_tests::state(&mut events);
+    state.animations_enabled = false;
+    let output = Output::new(
+        "test".into(),
+        smithay::output::PhysicalProperties {
+            size: (0, 0).into(),
+            subpixel: smithay::output::Subpixel::Unknown,
+            make: "test".into(),
+            model: "test".into(),
+        },
+    );
+    output.change_current_state(
+        Some(smithay::output::Mode {
+            size: (800, 600).into(),
+            refresh: 60_000,
+        }),
+        None,
+        None,
+        None,
+    );
+    state.space.map_output(&output, (0, 0));
+    state.register_output(&output, "test".into());
+    (events, state, output)
+}
+
+#[test]
+fn hidden_null_commit_removes_membership_and_remaps_without_workspace_switch() {
+    if !crate::startup_tests::private_runtime(
+        "state::window_lifecycle_tests::hidden_null_commit_removes_membership_and_remaps_without_workspace_switch",
+    ) {
+        return;
+    }
+
+    let (mut events, mut state, _) = fixture();
+    let (window, mut wire) = window(&mut state, &mut events, 0xff112233);
+    let id = state.windows.ids()[&window];
+    state.switch_workspace(2);
+    let active = state.workspaces.active_id();
+    assert!(state.space.element_location(&window).is_none());
+    assert_eq!(
+        state.window_for_surface(window.toplevel().unwrap().wl_surface()),
+        Some(window.clone())
+    );
+
+    request(&mut wire, 2, 1, &[0, 0, 0], None);
+    request(&mut wire, 2, 6, &[], None);
+    dispatch(&mut events, &mut state);
+    assert!(!state.windows.ids().contains_key(&window));
+    assert!(state.workspaces.workspace_for_window(id).is_none());
+
+    request(&mut wire, 2, 6, &[], None);
+    dispatch(&mut events, &mut state);
+    ack_configure(&mut wire, 3);
+    request(&mut wire, 2, 1, &[6, 0, 0], None);
+    request(&mut wire, 2, 6, &[], None);
+    dispatch(&mut events, &mut state);
+    let remapped = state.windows.ids()[&window];
+    assert_ne!(id, remapped);
+    assert_eq!(state.workspaces.workspace_for_window(remapped), Some(active));
+    assert_eq!(state.workspaces.active_id(), active);
+}
+
+#[test]
+fn hidden_commits_update_client_geometry_and_release_resize_transactions() {
+    if !crate::startup_tests::private_runtime(
+        "state::window_lifecycle_tests::hidden_commits_update_client_geometry_and_release_resize_transactions",
+    ) {
+        return;
+    }
+
+    let (mut events, mut state, _) = fixture();
+    let (window, mut wire) = window(&mut state, &mut events, 0xff112233);
+    let id = state.windows.ids()[&window];
+    state.switch_workspace(2);
+    assert!(state.space.element_location(&window).is_none());
+    let toplevel = window.toplevel().unwrap();
+    toplevel.with_pending_state(|pending| pending.size = Some((80, 48).into()));
+    let serial = toplevel.send_configure();
+    state.windows.set_transaction(
+        id,
+        crate::resize_transaction::ResizeTransaction::new(serial, state.presentation_now()),
+    );
+    state.display_handle.flush_clients().unwrap();
+    assert_eq!(ack_configure(&mut wire, 3), u32::from(serial));
+    request(&mut wire, 3, 3, &[0, 0, 32, 48], None);
+    request(&mut wire, 2, 1, &[6, 0, 0], None);
+    request(&mut wire, 2, 6, &[], None);
+    dispatch(&mut events, &mut state);
+    assert_eq!(window.geometry().size, (32, 48).into());
+    assert!(state.windows.transaction(&id).is_none());
+    assert_eq!(
+        state.windows.geometry(&id).unwrap().client.committed_size,
+        Some(ClientSize { width: 32, height: 48 })
+    );
+    assert!(state.space.element_location(&window).is_none());
+}
+
+#[test]
+fn floating_maximize_and_restore_work_in_both_layouts() {
+    if !crate::startup_tests::private_runtime(
+        "state::window_lifecycle_tests::floating_maximize_and_restore_work_in_both_layouts",
+    ) {
+        return;
+    }
+
+    let (mut events, mut state, _) = fixture();
+    let (window, mut wire) = window(&mut state, &mut events, 0xff112233);
+    let id = state.windows.ids()[&window];
+    state.focused_window = Some(id);
+    state.toggle_focused_floating();
+    state.set_floating_window_geometry(&window, (120, 100).into(), (64, 48).into());
+    state.display_handle.flush_clients().unwrap();
+    ack_configure(&mut wire, 3);
+    request(&mut wire, 2, 6, &[], None);
+    dispatch(&mut events, &mut state);
+    let normal = match state.workspaces.placement(id).unwrap() {
+        WindowPlacement::Floating { rect } => rect,
+        _ => panic!("expected floating window"),
+    };
+
+    let mut next_object = 7;
+    for mode in [ferese_core::LayoutMode::Scrolling, ferese_core::LayoutMode::Tree] {
+        let bounds = state.output_bounds().unwrap();
+        state.workspaces.set_active_layout_mode(mode, bounds).unwrap();
+        state.relayout();
+        state.set_window_maximized(id, true);
+        let maximized = maximized_rect(bounds, state.gap_config.outer);
+        assert_eq!(state.windows.geometry(&id).unwrap().logical, maximized, "{mode:?}");
+        assert_eq!(
+            state.workspaces.placement(id),
+            Some(WindowPlacement::Floating { rect: normal })
+        );
+        state.display_handle.flush_clients().unwrap();
+        ack_configure(&mut wire, 3);
+        // Commit the configured raster instead of keeping the original tiny buffer.
+        use smithay::reexports::wayland_server::protocol::wl_shm::WlShm;
+        use std::io::Write;
+        use std::os::fd::AsRawFd;
+        let client = window.toplevel().unwrap().wl_surface().client().unwrap();
+        let shm = client
+            .create_resource::<WlShm, (), Ferese>(&state.display_handle, 1, ())
+            .unwrap();
+        let (width, height) = (maximized.width.round() as u32, maximized.height.round() as u32);
+        let mut file = tempfile::tempfile().unwrap();
+        file.write_all(&0xff112233u32.to_ne_bytes().repeat((width * height) as usize))
+            .unwrap();
+        request(
+            &mut wire,
+            shm.id().protocol_id(),
+            0,
+            &[next_object, width * height * 4],
+            Some(file.as_raw_fd()),
+        );
+        request(
+            &mut wire,
+            next_object,
+            0,
+            &[next_object + 1, 0, width, height, width * 4, 0],
+            None,
+        );
+        request(&mut wire, 3, 3, &[0, 0, width, height], None);
+        request(&mut wire, 2, 1, &[next_object + 1, 0, 0], None);
+        next_object += 2;
+        request(&mut wire, 2, 6, &[], None);
+        dispatch(&mut events, &mut state);
+        assert!(
+            window
+                .toplevel()
+                .unwrap()
+                .current_state()
+                .states
+                .contains(xdg_toplevel::State::Maximized)
+        );
+
+        state.set_window_maximized(id, false);
+        assert_eq!(state.windows.geometry(&id).unwrap().logical, normal, "{mode:?}");
+        state.display_handle.flush_clients().unwrap();
+        ack_configure(&mut wire, 3);
+        request(&mut wire, 3, 3, &[0, 0, 64, 48], None);
+        request(&mut wire, 2, 1, &[6, 0, 0], None);
+        request(&mut wire, 2, 6, &[], None);
+        dispatch(&mut events, &mut state);
+        assert!(
+            !window
+                .toplevel()
+                .unwrap()
+                .current_state()
+                .states
+                .contains(xdg_toplevel::State::Maximized)
+        );
+        assert_eq!(
+            state.workspaces.placement(id),
+            Some(WindowPlacement::Floating { rect: normal })
+        );
+    }
+}
+
+#[test]
+fn malformed_resize_limits_disconnect_only_the_client_and_motion_survives() {
+    use std::io::Read;
+    if !crate::startup_tests::private_runtime(
+        "state::window_lifecycle_tests::malformed_resize_limits_disconnect_only_the_client_and_motion_survives",
+    ) {
+        return;
+    }
+
+    let (mut events, mut state, _) = fixture();
+    for (minimum, maximum) in [
+        ((800, 0), (400, 0)),
+        ((0, 800), (0, 400)),
+        ((-1, 0), (0, 0)),
+        ((0, 0), (-1, 0)),
+        ((0, -1), (0, 0)),
+        ((0, 0), (0, -1)),
+    ] {
+        let (window, mut wire) = window(&mut state, &mut events, 0xff112233);
+        let id = state.windows.ids()[&window];
+        state.focused_window = Some(id);
+        state.toggle_focused_floating();
+        let pointer = state.seat.get_pointer().unwrap();
+        pointer.set_grab(
+            &mut state,
+            crate::grabs::ResizeSurfaceGrab::new(
+                GrabStartData {
+                    focus: None,
+                    button: 0x110,
+                    location: (100.0, 100.0).into(),
+                },
+                window,
+                xdg_toplevel::ResizeEdge::BottomRight.into(),
+                Rectangle::new((100, 100).into(), (64, 48).into()),
+            ),
+            SERIAL_COUNTER.next_serial(),
+            Focus::Clear,
+        );
+        request(&mut wire, 4, 8, &[minimum.0 as u32, minimum.1 as u32], None);
+        request(&mut wire, 4, 7, &[maximum.0 as u32, maximum.1 as u32], None);
+        request(&mut wire, 2, 6, &[], None);
+        dispatch(&mut events, &mut state);
+        pointer.motion(
+            &mut state,
+            None,
+            &MotionEvent {
+                location: (120.0, 130.0).into(),
+                serial: SERIAL_COUNTER.next_serial(),
+                time: 1,
+            },
+        );
+        pointer.unset_grab(&mut state, SERIAL_COUNTER.next_serial(), 2);
+        wire.set_nonblocking(true).unwrap();
+        let mut messages = Vec::new();
+        let _ = wire.read_to_end(&mut messages);
+        let mut offset = 0;
+        let mut rejected = false;
+        while offset + 8 <= messages.len() {
+            let object = u32::from_ne_bytes(messages[offset..offset + 4].try_into().unwrap());
+            let header = u32::from_ne_bytes(messages[offset + 4..offset + 8].try_into().unwrap());
+            if object == 1 && header & 0xffff == 0 {
+                assert_eq!(
+                    u32::from_ne_bytes(messages[offset + 12..offset + 16].try_into().unwrap()),
+                    xdg_toplevel::Error::InvalidSize as u32
+                );
+                rejected = true;
+            }
+
+            offset += (header >> 16) as usize;
+        }
+        assert!(rejected, "invalid limits {minimum:?}/{maximum:?} were not rejected");
+    }
+
+    let (healthy, _wire) = window(&mut state, &mut events, 0xff112233);
+    assert!(state.windows.ids().contains_key(&healthy));
+}

compositor/src/state/windows.rs

@@ -1,6 +1,20 @@
 use super::*;
 
 impl Ferese {
+    pub(crate) fn window_for_surface(&self, surface: &WlSurface) -> Option<Window> {
+        self.windows
+            .id_for_surface(surface)
+            .and_then(|id| self.windows.window(id))
+            .or_else(|| {
+                self.space.elements().find(|window| {
+                    window
+                        .toplevel()
+                        .is_some_and(|toplevel| toplevel.wl_surface() == surface)
+                })
+            })
+            .cloned()
+    }
+
     pub(crate) fn restore_initial_floating_size(&mut self, window: &Window) {
         let Some(toplevel) = window.toplevel() else { return };
         let (app_id, title, transient) = with_states(toplevel.wl_surface(), |states| {
@@ -449,17 +463,10 @@ impl Ferese {
     }
 
     pub(crate) fn capture_resize_before_commit(&mut self, surface: &WlSurface) {
-        let Some((window, id)) = self
-            .windows
-            .ids()
-            .iter()
-            .find(|(window, _)| {
-                window
-                    .toplevel()
-                    .is_some_and(|toplevel| toplevel.wl_surface() == surface)
-            })
-            .map(|(window, id)| (window.clone(), *id))
-        else {
+        let Some(id) = self.windows.id_for_surface(surface) else {
+            return;
+        };
+        let Some(window) = self.windows.window(id).cloned() else {
             return;
         };
 

compositor/src/theme.rs

@@ -97,7 +97,7 @@ static SYSTEM_APPEARANCE: std::sync::OnceLock<Mutex<Option<ferese_config::theme:
 
 fn auto_context() -> ferese_config::theme::AutoContext {
     let appearance = SYSTEM_APPEARANCE.get_or_init(|| {
-        let value = std::process::Command::new("gsettings")
+        let value = crate::process::command("gsettings")
             .args(["get", "org.gnome.desktop.interface", "color-scheme"])
             .output()
             .ok()
@@ -323,7 +323,7 @@ pub(crate) fn init(
         .spawn(move || {
             use std::io::BufRead;
             use std::os::unix::process::CommandExt;
-            let mut command = std::process::Command::new("gsettings");
+            let mut command = crate::process::command("gsettings");
             unsafe {
                 command.pre_exec(|| {
                     if libc::prctl(libc::PR_SET_PDEATHSIG, libc::SIGTERM) == -1 {
@@ -338,7 +338,7 @@ pub(crate) fn init(
                 .stderr(std::process::Stdio::null())
                 .spawn();
             if let Ok(mut monitor) = monitor {
-                if let Ok(output) = std::process::Command::new("gsettings")
+                if let Ok(output) = crate::process::command("gsettings")
                     .args(["get", "org.gnome.desktop.interface", "color-scheme"])
                     .output()
                 {
@@ -430,8 +430,7 @@ impl Ferese {
             self.poll_theme();
             return;
         }
-        let wallpaper = (self.wallpaper.configuration() != &wallpaper)
-            .then(|| WallpaperState::with_wakeup(wallpaper, Some(self.loop_signal.clone())));
+        let wallpaper = (self.wallpaper.configuration() != &wallpaper).then(|| self.wallpaper.replacement(wallpaper));
         self.theme_engine.pending = Some(Pending {
             candidate,
             wallpaper,

compositor/src/wallpaper.rs

@@ -18,8 +18,11 @@ use smithay::utils::{Buffer, Physical, Rectangle, Size};
 
 use crate::presentation::NativeTextureElement;
 
+mod decoder;
 mod pixels;
+use decoder::Decoder;
 use pixels::Pixels;
+use std::sync::Arc;
 
 const UPLOAD_RETRY_DELAY: Duration = Duration::from_secs(5);
 
@@ -59,6 +62,8 @@ struct WallpaperTexture {
 pub(crate) struct WallpaperState {
     config: WallpaperConfig,
     pending: Option<WallpaperConfig>,
+    loading: Option<WallpaperConfig>,
+    decoder: Arc<Decoder>,
     commit: CommitCounter,
     owned: bool,
     mode: WallpaperMode,
@@ -78,26 +83,35 @@ impl WallpaperState {
     }
 
     pub fn with_wakeup(config: WallpaperConfig, wakeup: Option<smithay::reexports::calloop::LoopSignal>) -> Self {
+        Self::with_decoder(config, wakeup, Decoder::new(pixels::load))
+    }
+
+    pub(crate) fn replacement(&self, config: WallpaperConfig) -> Self {
+        Self::with_decoder(config, self.wakeup.clone(), self.decoder.clone())
+    }
+
+    fn with_decoder(
+        config: WallpaperConfig,
+        wakeup: Option<smithay::reexports::calloop::LoopSignal>,
+        decoder: Arc<Decoder>,
+    ) -> Self {
         let retained = config.clone();
-        let (sender, receiver) = mpsc::channel();
         let owned = config.path.as_ref().is_some_and(|path| path.is_file());
-        if owned {
-            let path = config.path.unwrap();
-            let wakeup = wakeup.clone();
-            std::thread::spawn(move || {
-                let _ = sender.send(pixels::load(&path));
-                if let Some(wakeup) = wakeup {
-                    wakeup.wakeup();
-                }
-            });
-        }
+        let receiver = if owned {
+            Some(decoder.submit(config.path.clone().unwrap(), wakeup.clone()))
+        } else {
+            decoder.cancel_pending();
+            None
+        };
         Self {
             config: retained,
             pending: None,
+            loading: None,
+            decoder,
             commit: CommitCounter::default(),
             owned,
             mode: config.mode,
-            receiver: owned.then_some(receiver),
+            receiver,
             pixels: None,
             textures: HashMap::new(),
             upload_retries: HashMap::new(),
@@ -121,8 +135,22 @@ impl WallpaperState {
     }
 
     pub fn reload(&mut self, config: WallpaperConfig) {
+        if self.config.path != config.path && config.path.as_ref().is_some_and(|path| !path.is_file()) {
+            tracing::warn!("new wallpaper is unavailable; retaining previous image");
+            return;
+        }
+
         if self.receiver.is_some() {
-            self.pending = (self.config != config).then_some(config);
+            if self.loading.is_some() && self.config == config {
+                self.receiver = None;
+                self.loading = None;
+                self.pending = None;
+                self.decoder.cancel_pending();
+                return;
+            }
+
+            let requested = self.loading.as_ref().unwrap_or(&self.config);
+            self.pending = (requested != &config).then_some(config);
             return;
         }
         if self.config == config {
@@ -134,19 +162,18 @@ impl WallpaperState {
             self.commit.increment();
             return;
         }
-        if config.path.as_ref().is_some_and(|path| !path.is_file()) {
-            tracing::warn!("new wallpaper is unavailable; retaining previous image");
-            return;
-        }
-        let mut replacement = Self::with_wakeup(config, self.wakeup.clone());
-        self.config = replacement.config;
-        self.mode = replacement.mode;
-        self.owned = replacement.owned;
-        self.receiver = replacement.receiver.take();
-        if self.config.path.is_none() {
+        if let Some(path) = config.path.clone() {
+            self.receiver = Some(self.decoder.submit(path, self.wakeup.clone()));
+            self.loading = Some(config);
+        } else {
+            self.decoder.cancel_pending();
+            self.config = config;
+            self.mode = self.config.mode;
+            self.owned = false;
             self.pixels = None;
             self.textures.clear();
             self.upload_retries.clear();
+            self.commit.increment();
         }
     }
 
@@ -205,16 +232,15 @@ impl WallpaperState {
         match receiver.try_recv() {
             Ok(result) => {
                 self.receiver = None;
-                if let Some(pending) = self.pending.take() {
-                    if pending.path != self.config.path {
-                        self.reload(pending);
-                        return true;
-                    }
-                    self.config = pending;
-                    self.mode = self.config.mode;
-                }
+                let loading = self.loading.take();
                 match result {
                     Ok(pixels) => {
+                        if let Some(config) = loading {
+                            self.config = config;
+                            self.mode = self.config.mode;
+                            self.owned = true;
+                        }
+
                         tracing::info!(
                             width = pixels.width(),
                             height = pixels.height(),
@@ -227,13 +253,17 @@ impl WallpaperState {
                         self.commit.increment();
                     }
                     Err(error) => {
-                        tracing::warn!(%error, "wallpaper unavailable; using output clear color")
+                        tracing::warn!(%error, "wallpaper decode failed; retaining previous image")
                     }
                 }
+                if let Some(pending) = self.pending.take() {
+                    self.reload(pending);
+                }
                 true
             }
             Err(mpsc::TryRecvError::Disconnected) => {
                 self.receiver = None;
+                self.loading = None;
                 false
             }
             Err(mpsc::TryRecvError::Empty) => false,
@@ -323,6 +353,46 @@ fn image_geometry(
 mod tests {
     use super::*;
 
+    #[test]
+    fn failed_reload_preserves_accepted_config_and_unavailable_pending_keeps_success() {
+        let directory = tempfile::tempdir().unwrap();
+        let mut state = WallpaperState::new(WallpaperConfig {
+            path: None,
+            mode: WallpaperMode::Fill,
+        });
+        let accepted = state.config.clone();
+        state.pixels = Some(pixels::from_rgba(image::RgbaImage::new(2, 2)).unwrap());
+        let bad = directory.path().join("bad-image");
+        std::fs::write(&bad, b"not an image").unwrap();
+        state.reload(WallpaperConfig {
+            path: Some(bad),
+            mode: WallpaperMode::Fit,
+        });
+        let deadline = Instant::now() + Duration::from_secs(2);
+        while !state.poll() {
+            assert!(Instant::now() < deadline);
+            std::thread::sleep(Duration::from_millis(1));
+        }
+
+        assert_eq!(state.config, accepted);
+        assert_eq!(state.pixels.as_ref().unwrap().dimensions(), (2, 2));
+        let (sender, receiver) = mpsc::channel();
+        state.receiver = Some(receiver);
+        state.reload(WallpaperConfig {
+            path: Some(directory.path().join("missing")),
+            mode: WallpaperMode::Fit,
+        });
+        sender
+            .send(Ok(pixels::from_rgba(image::RgbaImage::new(3, 4)).unwrap()))
+            .unwrap();
+        assert!(state.poll());
+        assert_eq!(state.pixels.as_ref().unwrap().dimensions(), (3, 4));
+        assert_eq!(state.config, accepted);
+
+        let replacement = state.replacement(accepted);
+        assert!(Arc::ptr_eq(&state.decoder, &replacement.decoder));
+    }
+
     #[test]
     fn portal_wallpaper_decodes_without_a_filename_extension() {
         let directory = tempfile::tempdir().unwrap();

compositor/src/wallpaper/decoder.rs

@@ -0,0 +1,114 @@
+//! One in-flight decode and one replaceable request across wallpaper states.
+use std::path::{Path, PathBuf};
+use std::sync::{Arc, Condvar, Mutex, mpsc};
+
+use super::pixels::Pixels;
+
+struct Request {
+    path: PathBuf,
+    result: mpsc::Sender<Result<Pixels, String>>,
+    wakeup: Option<smithay::reexports::calloop::LoopSignal>,
+}
+
+#[derive(Default)]
+struct Queue {
+    pending: Option<Request>,
+    closed: bool,
+}
+
+pub(super) struct Decoder {
+    shared: Arc<(Mutex<Queue>, Condvar)>,
+}
+
+impl Decoder {
+    pub fn new(load: impl Fn(&Path) -> Result<Pixels, String> + Send + 'static) -> Arc<Self> {
+        let shared = Arc::new((Mutex::new(Queue::default()), Condvar::new()));
+        let worker = shared.clone();
+        std::thread::Builder::new()
+            .name("ferese-wallpaper".into())
+            .spawn(move || {
+                loop {
+                    let (queue, ready) = &*worker;
+                    let mut queue = ready
+                        .wait_while(queue.lock().unwrap(), |queue| !queue.closed && queue.pending.is_none())
+                        .unwrap();
+                    if queue.closed {
+                        break;
+                    }
+
+                    let request = queue.pending.take().unwrap();
+                    drop(queue);
+                    let _ = request.result.send(load(&request.path));
+                    if let Some(wakeup) = request.wakeup {
+                        wakeup.wakeup();
+                    }
+                }
+            })
+            .expect("start wallpaper decoder");
+        Arc::new(Self { shared })
+    }
+
+    pub fn submit(
+        &self,
+        path: PathBuf,
+        wakeup: Option<smithay::reexports::calloop::LoopSignal>,
+    ) -> mpsc::Receiver<Result<Pixels, String>> {
+        let (result, receiver) = mpsc::channel();
+        let (queue, ready) = &*self.shared;
+        queue.lock().unwrap().pending = Some(Request { path, result, wakeup });
+        ready.notify_one();
+        receiver
+    }
+
+    pub fn cancel_pending(&self) {
+        self.shared.0.lock().unwrap().pending = None;
+    }
+}
+
+impl Drop for Decoder {
+    fn drop(&mut self) {
+        let (queue, ready) = &*self.shared;
+        let mut queue = queue.lock().unwrap();
+        queue.closed = true;
+        queue.pending = None;
+        ready.notify_one();
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::time::Duration;
+
+    #[test]
+    fn replacements_share_one_decode_and_only_the_latest_pending_starts() {
+        let (started, events) = mpsc::channel();
+        let (release, held) = mpsc::channel();
+        let decoder = Decoder::new(move |path| {
+            started.send(path.to_owned()).unwrap();
+            if path == Path::new("first") {
+                held.recv_timeout(Duration::from_secs(2)).unwrap();
+            }
+            Err("test decode".into())
+        });
+        let first = decoder.submit("first".into(), None);
+        assert_eq!(
+            events.recv_timeout(Duration::from_secs(2)).unwrap(),
+            PathBuf::from("first")
+        );
+        let dropped = decoder.submit("second".into(), None);
+        let dropped_too = decoder.submit("third".into(), None);
+        let latest = decoder.submit("latest".into(), None);
+        assert!(events.try_recv().is_err());
+        assert!(matches!(dropped.try_recv(), Err(mpsc::TryRecvError::Disconnected)));
+        assert!(matches!(dropped_too.try_recv(), Err(mpsc::TryRecvError::Disconnected)));
+        release.send(()).unwrap();
+        assert!(first.recv_timeout(Duration::from_secs(2)).unwrap().is_err());
+        assert_eq!(
+            events.recv_timeout(Duration::from_secs(2)).unwrap(),
+            PathBuf::from("latest")
+        );
+        assert!(latest.recv_timeout(Duration::from_secs(2)).unwrap().is_err());
+        assert!(events.try_recv().is_err());
+    }
+}

compositor/src/winit.rs

@@ -155,7 +155,7 @@ pub fn init(event_loop: &mut EventLoop<Ferese>, state: &mut Ferese) -> Result<()
                                     &mut capture_texture,
                                     &output,
                                     &scene,
-                                )?;
+                                );
                                 capture_changed_binding = true;
                             }
                             if capture_changed_binding {