Fix review findings across compositor and shell

compositor/src/input.rs

@@ -1308,7 +1308,7 @@ fn virtual_terminal(symbol: u32, ctrl: bool, alt: bool, direct: bool) -> Option<
     }
 
     (ctrl && alt && (keysyms::KEY_F1..=keysyms::KEY_F12).contains(&symbol))
-        .then_some((symbol - keysyms::KEY_F1 + 1) as i32)
+        .then(|| (symbol - keysyms::KEY_F1 + 1) as i32)
 }
 
 fn emergency_shortcut_escape(symbol: u32, ctrl: bool, alt: bool) -> bool {
@@ -1394,6 +1394,17 @@ mod tests {
         assert_eq!(virtual_terminal(keysyms::KEY_F7, false, true, true), None);
     }
 
+    #[test]
+    fn ordinary_keys_never_evaluate_virtual_terminal_arithmetic() {
+        for symbol in [0, keysyms::KEY_a, keysyms::KEY_Escape, keysyms::KEY_F12 + 1] {
+            for ctrl in [false, true] {
+                for alt in [false, true] {
+                    assert_eq!(virtual_terminal(symbol, ctrl, alt, true), None);
+                }
+            }
+        }
+    }
+
     #[test]
     fn leaves_virtual_terminal_keys_to_nested_clients() {
         assert_eq!(