Restore floating window size before the first buffer

compositor/src/handlers/compositor.rs

@@ -77,6 +77,12 @@ impl CompositorHandler for Ferese {
                         self.space.map_element(window.clone(), (0, 0), false);
                         self.restore_keyboard_focus();
                     }
+                    if window
+                        .toplevel()
+                        .is_some_and(|toplevel| !xdg_shell::initial_configure_sent(toplevel))
+                    {
+                        self.restore_initial_floating_size(&window);
+                    }
                 }
                 self.record_client_commit(&window);
             }

compositor/src/handlers/xdg_shell.rs

@@ -285,12 +285,14 @@ impl XdgDecorationHandler for Ferese {
         let mode = self.decoration_mode_for(&toplevel);
         toplevel.with_pending_state(|state| state.decoration_mode = Some(mode));
 
-        // This must be unconditional: the initial xdg-toplevel configure may
+        // Wait for the initial surface commit so app-id and saved floating
-        // already contain the same mode before the decoration object exists.
+        // size can be included in the first configure. If already configured,
-        // `send_pending_configure` would then see no state change and omit the
+        // send unconditionally: the existing toplevel state may have the same
-        // decoration configure, leaving clients to fall back to CSD.
+        // mode, but the new decoration object still needs its configure event.
+        if initial_configure_sent(&toplevel) {
             toplevel.send_configure();
         }
+    }
 
     fn request_mode(&mut self, toplevel: ToplevelSurface, _mode: Mode) {
         let mode = self.decoration_mode_for(&toplevel);
@@ -319,8 +321,22 @@ impl Ferese {
 
 fn set_decoration_mode(toplevel: &ToplevelSurface, mode: Mode) {
     toplevel.with_pending_state(|state| state.decoration_mode = Some(mode));
+    if initial_configure_sent(toplevel) {
         toplevel.send_pending_configure();
     }
+}
+
+pub(crate) fn initial_configure_sent(toplevel: &ToplevelSurface) -> bool {
+    with_states(toplevel.wl_surface(), |states| {
+        states
+            .data_map
+            .get::<XdgToplevelSurfaceData>()
+            .unwrap()
+            .lock()
+            .unwrap()
+            .initial_configure_sent
+    })
+}
 
 pub fn handle_commit(popups: &mut PopupManager, space: &mut Space<Window>, surface: &WlSurface) {
     handle_resize_commit(surface);

compositor/src/state.rs

@@ -1257,6 +1257,54 @@ impl Ferese {
                 .is_some_and(|geometry| geometry.client.committed_size.is_some())
     }
 
+    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| {
+            let attributes = states.data_map.get::<XdgToplevelSurfaceData>().unwrap().lock().unwrap();
+            (
+                attributes.app_id.clone(),
+                attributes.title.clone(),
+                attributes.parent.is_some(),
+            )
+        });
+        let special_mode = toplevel.with_pending_state(|pending| {
+            pending.states.contains(xdg_toplevel::State::Fullscreen)
+                || pending.states.contains(xdg_toplevel::State::Maximized)
+        });
+        let rule = resolve_window_rules(&self.window_rules, app_id.as_deref(), title.as_deref(), transient);
+        if transient
+            || special_mode
+            || rule.fullscreen == Some(true)
+            || !rule.floating.unwrap_or(rule.width.is_some() || rule.height.is_some())
+        {
+            return;
+        }
+        let outputs = self.floating_outputs();
+        let Some((remembered, work)) = app_id
+            .as_deref()
+            .and_then(|app| self.floating_memory.get(app))
+            .and_then(|entry| {
+                let rect = entry.restore(&outputs)?;
+                let work = outputs.iter().find(|(name, _)| *name == entry.output)?.1;
+                Some((rect, work))
+            })
+        else {
+            return;
+        };
+        // Metadata is available on the initial bufferless commit. Restore the
+        // size before the client creates its first buffer, without mapping or
+        // focusing the window. Use the same rule/constraint precedence as map.
+        let rect = self.place_floating(
+            window,
+            None,
+            work,
+            (remembered.width, remembered.height),
+            Some((rule.width, rule.height)),
+        );
+        let size = ClientSize::from_rect(rect);
+        toplevel.with_pending_state(|pending| pending.size = Some((size.width, size.height).into()));
+    }
+
     pub(crate) fn add_rule_placed_window(
         &mut self,
         window: Window,

scripts/tests/fixtures/floating-size.c

@@ -8,6 +8,10 @@
 #include <unistd.h>
 #include <wayland-client.h>
 #include "xdg-shell-client-protocol.h"
+#ifdef FERESE_TEST_DECORATION
+#include "xdg-decoration-client-protocol.h"
+static struct zxdg_decoration_manager_v1 *decoration_manager;
+#endif
 
 static struct wl_compositor *compositor;
 static struct wl_shm *shm;
@@ -50,6 +54,10 @@ static void global(void *data, struct wl_registry *registry, uint32_t name,
         wm = wl_registry_bind(registry, name, &xdg_wm_base_interface, 1);
         xdg_wm_base_add_listener(wm, &wm_listener, NULL);
     }
+#ifdef FERESE_TEST_DECORATION
+    else if (!strcmp(interface, "zxdg_decoration_manager_v1"))
+        decoration_manager = wl_registry_bind(registry, name, &zxdg_decoration_manager_v1_interface, 1);
+#endif
 }
 static void removed(void *data, struct wl_registry *registry, uint32_t name) {
     (void)data; (void)registry; (void)name;
@@ -59,6 +67,8 @@ static void configure(void *data, struct xdg_surface *xdg, uint32_t serial) {
     (void)data;
     xdg_surface_ack_configure(xdg, serial);
     make_buffer();
+    printf("buffer %d %d\n", width, height);
+    fflush(stdout);
     xdg_surface_set_window_geometry(xdg, 0, 0, width, height);
     wl_surface_attach(surface, buffer, 0, 0);
     wl_surface_damage(surface, 0, 0, width, height);
@@ -68,6 +78,8 @@ static const struct xdg_surface_listener surface_listener = {.configure = config
 static void size(void *data, struct xdg_toplevel *top, int32_t w, int32_t h,
                  struct wl_array *states) {
     (void)data; (void)top; (void)states;
+    printf("configure %d %d\n", w, h);
+    fflush(stdout);
     if (honor_configure) {
         if (w > 0) width = w;
         if (h > 0) height = h;
@@ -77,6 +89,12 @@ static void close_window(void *data, struct xdg_toplevel *top) {
     (void)data; (void)top; exit(0);
 }
 static const struct xdg_toplevel_listener top_listener = {.configure = size, .close = close_window};
+#ifdef FERESE_TEST_DECORATION
+static void decoration_configure(void *data, struct zxdg_toplevel_decoration_v1 *decoration, uint32_t mode) {
+    (void)data; (void)decoration; (void)mode;
+}
+static const struct zxdg_toplevel_decoration_v1_listener decoration_listener = {.configure = decoration_configure};
+#endif
 int main(int argc, char **argv) {
     if (argc >= 4) { width = atoi(argv[2]); height = atoi(argv[3]); }
     honor_configure = argc >= 5;
@@ -91,6 +109,15 @@ int main(int argc, char **argv) {
     xdg_surface_add_listener(xdg, &surface_listener, NULL);
     struct xdg_toplevel *top = xdg_surface_get_toplevel(xdg);
     xdg_toplevel_add_listener(top, &top_listener, NULL);
+#ifdef FERESE_TEST_DECORATION
+    if (argc >= 6 && !strcmp(argv[5], "decorated")) {
+        if (!decoration_manager) return 6;
+        struct zxdg_toplevel_decoration_v1 *decoration =
+            zxdg_decoration_manager_v1_get_toplevel_decoration(decoration_manager, top);
+        zxdg_toplevel_decoration_v1_add_listener(decoration, &decoration_listener, NULL);
+        zxdg_toplevel_decoration_v1_set_mode(decoration, ZXDG_TOPLEVEL_DECORATION_V1_MODE_CLIENT_SIDE);
+    }
+#endif
     xdg_toplevel_set_app_id(top, argc >= 2 ? argv[1] : "ferese.test.floating-size");
     xdg_toplevel_set_title(top, "Floating size regression");
     wl_surface_commit(surface);

scripts/tests/test_floating_placement_isolated.py

@@ -23,21 +23,32 @@ class FloatingPlacementTest(unittest.TestCase):
             xml = str(Path(protocols) / "stable/xdg-shell/xdg-shell.xml")
             for kind, output in [("client-header", "xdg-shell-client-protocol.h"), ("private-code", "xdg-shell-protocol.c")]:
                 subprocess.run(["wayland-scanner", kind, xml, str(root / output)], check=True)
+            decoration_xml = str(Path(protocols) / "unstable/xdg-decoration/xdg-decoration-unstable-v1.xml")
+            for kind, output in [("client-header", "xdg-decoration-client-protocol.h"),
+                                 ("private-code", "xdg-decoration-protocol.c")]:
+                subprocess.run(["wayland-scanner", kind, decoration_xml, str(root / output)], check=True)
             flags = subprocess.check_output(["pkg-config", "--cflags", "--libs", "wayland-client"], text=True).split()
-            subprocess.run(["cc", "-Wall", "-Wextra", "-I", str(root), str(repo / "scripts/tests/fixtures/floating-size.c"),
+            subprocess.run(["cc", "-Wall", "-Wextra", "-DFERESE_TEST_DECORATION", "-I", str(root),
-                            str(root / "xdg-shell-protocol.c"), "-o", str(root / "client"), *flags], check=True)
+                            str(repo / "scripts/tests/fixtures/floating-size.c"), str(root / "xdg-shell-protocol.c"),
+                            str(root / "xdg-decoration-protocol.c"), "-o", str(root / "client"), *flags], check=True)
             runtime = root / "runtime"
             runtime.mkdir(mode=0o700)
             config = root / "config/ferese"
             config.mkdir(parents=True)
-            (config / "config.kdl").write_text('animations { enabled #false; }\n' + ''.join(
+            (config / "config.kdl").write_text('animations { enabled #true; }\n' + ''.join(
                 f'window-rule app-id="ferese.test.placement.{app}" floating=#true\n' for app in ["remembered", "second", "third"]) +
                 'window-rule app-id="ferese.test.placement.fullscreen" floating=#true width=240 height=160 fullscreen=#true\n' +
-                'window-rule app-id="ferese.test.placement.maximized" floating=#true width=240 height=160\n')
+                'window-rule app-id="ferese.test.placement.maximized" floating=#true width=240 height=160\n' +
+                'window-rule app-id="ferese.test.placement.reopen" floating=#true\n' +
+                'window-rule app-id="ferese.test.placement.rule-size" floating=#true width=300 height=190\n')
             state = root / "state/ferese"
             state.mkdir(parents=True)
             memory = state / "floating.json"
-            memory.write_text(json.dumps({"ferese.test.placement.remembered": {"output": "ferese-winit", "fractions": [.1, .1, .2, .2]}}))
+            memory.write_text(json.dumps({"ferese.test.placement." + app: {"output": "ferese-winit", "fractions": fractions}
+                                         for app, fractions in [("remembered", [.1, .1, .2, .2]),
+                                                                ("reopen", [.55, .55, .25, .3]),
+                                                                ("rule-size", [.55, .55, .25, .3]),
+                                                                ("tiled", [.55, .55, .25, .3])]}))
             before = memory.read_bytes()
             display = Path(os.environ["WAYLAND_DISPLAY"])
             if not display.is_absolute():
@@ -104,6 +115,49 @@ class FloatingPlacementTest(unittest.TestCase):
                             self.fail(f"floating rectangle changed after toggling: {expected} -> {actual}")
                         time.sleep(.025)
                     self.assertEqual(memory.read_bytes(), before, "nested previews must not persist drag memory")
+                    # The first configure and every buffer must already have
+                    # the restored size. Checking only the final rectangle
+                    # misses a visible default-size -> saved-size replay.
+                    for app, repeats in [("reopen", 2), ("rule-size", 1), ("tiled", 1)]:
+                        for attempt in range(repeats):
+                            with (root / f"{app}-{attempt}.log").open("w+") as client_log:
+                                args = [str(root / "client"), "ferese.test.placement." + app, "240", "160", "configured"]
+                                if attempt == 1:
+                                    # Request decorations before sending app-id:
+                                    # this must not send an early sizeless configure.
+                                    args.append("decorated")
+                                client = launch(args, stdout=client_log, stderr=log)
+                                deadline = time.monotonic() + 5
+                                while True:
+                                    client_log.seek(0)
+                                    events = client_log.read().splitlines()
+                                    buffers = [tuple(map(int, e.split()[1:])) for e in events if e.startswith("buffer ")]
+                                    if buffers:
+                                        break
+                                    if time.monotonic() > deadline:
+                                        self.fail(f"client did not map: {events}")
+                                    time.sleep(.01)
+                                first_configure = next(tuple(map(int, e.split()[1:])) for e in events if e.startswith("configure "))
+                                if app == "tiled":
+                                    self.assertEqual(first_configure, (0, 0), "floating memory must not size a tiled window")
+                                else:
+                                    output = next(o for o in command("get-outputs") if o["enabled"])
+                                    expected = ((round(.25 * output["width"]), round(.3 * output["height"]))
+                                                if app == "reopen" else (300, 190))
+                                    for actual, target in zip(first_configure, expected):
+                                        self.assertAlmostEqual(actual, target, delta=1)
+                                    time.sleep(.4)
+                                    client_log.seek(0)
+                                    buffers = [tuple(map(int, e.split()[1:])) for e in client_log.read().splitlines()
+                                               if e.startswith("buffer ")]
+                                    self.assertTrue(all(size == first_configure for size in buffers), repr(buffers))
+                                client.terminate()
+                                client.wait(timeout=3)
+                                deadline = time.monotonic() + 5
+                                while any(w["app_id"] == "ferese.test.placement." + app for w in command("get-windows")):
+                                    if time.monotonic() > deadline:
+                                        self.fail("closed client remained mapped")
+                                    time.sleep(.01)
                     for mode in ["fullscreen", "maximized"]:
                         app = "ferese.test.placement." + mode
                         if mode == "maximized":