Fix desktop-icon deselection and workspace-teleport-on-close; document a shadow limit

Desktop icons stayed highlighted after clicking a window: select_desktop_icon(None)
was only ever called from start_desktop_marquee, never from the one place every
focus path (click, Alt-Tab, dock IPC, scratchpad show, snap flyout) already
funnels through. Added the deselect there instead of per-caller.

Closing a focused window could silently switch the user's active workspace:
remove_window's fallback picked self.order.last(), but that list is global,
not per-workspace, so it could land on a background window elsewhere - and
focus_window already switches workspace to match whatever it's given (a real,
separate feature for a deliberate srd dispatch focus). Fixed by preferring a
same-workspace window first. New general.close_focus_follows_workspace
(default false, live-settable) controls what happens only when nothing is
left on the current workspace at all: off leaves focus at nothing, matching
Windows/GNOME/macOS; on restores the old always-follow-the-global-fallback
behaviour. Three new tests.

Also documented, not fixed: shadows can still bleed onto a neighbouring
*monitor* near a multi-output seam (shadow_rect has no monitor-boundary
awareness), found via a live cross-monitor screenshot. Moot for this
session since general.shadows is already off in the live config, but a
real, open gap for anyone who re-enables shadows on a multi-monitor setup.

3 files changed, 103 insertions, 1 deletions

diff --git a/crates/core/src/manager/mod.rs b/crates/core/src/manager/mod.rs
index d449486..9265885 100644
--- a/crates/core/src/manager/mod.rs
+++ b/crates/core/src/manager/mod.rs
@@ -241,6 +241,24 @@ pub struct WindowManager {
     /// see the Wayland backend's shadow render call site - so this only
     /// ever turns it off entirely, not on for those.
     pub shadows_enabled: bool,
+    /// Whether closing your own focused window is allowed to fall back to
+    /// a window on a *different* workspace and switch you there to follow
+    /// it, when nothing else is left on your current one. Read from
+    /// `general.close_focus_follows_workspace`. `false` (the default)
+    /// matches every mainstream desktop (Windows/GNOME/macOS never change
+    /// your active workspace just because a window closed) - `remove_
+    /// window`'s own fallback then only ever considers a same-workspace
+    /// window, leaving focus at `None` if there isn't one, rather than
+    /// picking whatever window was next in the *global* most-recently-
+    /// focused order regardless of which workspace it happens to be on.
+    /// Reported live as windows closing and "teleporting" the user to a
+    /// previous workspace - exactly this: the global fallback picking a
+    /// background window elsewhere, then `focus_window`'s own (separate,
+    /// correct, and unrelated to this setting) "switch workspace to match
+    /// the newly focused window" side effect following it there. `true`
+    /// restores that original always-follow behaviour for anyone who
+    /// wants it.
+    pub close_focus_follows_workspace: bool,
     /// Width, in pixels, of the resize grab band along a window's edges,
     /// read from `general.resize_margin`. See [`crate::window::RESIZE_MARGIN`]'s
     /// doc comment for the default and why it's what it is.
@@ -548,6 +566,7 @@ impl WindowManager {
             animations_enabled: true,
             animation_duration_ms: 200,
             shadows_enabled: true,
+            close_focus_follows_workspace: false,
             resize_margin: RESIZE_MARGIN,
             rounded_corners_enabled: None,
             gpu_enabled: false,
diff --git a/crates/core/src/manager/tests.rs b/crates/core/src/manager/tests.rs
index f703f25..6a3ba3f 100644
--- a/crates/core/src/manager/tests.rs
+++ b/crates/core/src/manager/tests.rs
@@ -11,6 +11,72 @@
     }
 
     #[test]
+    fn closing_the_focused_window_prefers_a_same_workspace_fallback_over_a_more_recent_global_one() {
+        let mut wm = wm_with_monitor();
+        let a = wm.alloc_window_id();
+        wm.add_window(Window::new(a, "a")); // workspace 1
+
+        let ws2 = wm.add_workspace("2", "dynamic");
+        wm.switch_workspace(ws2);
+        let c = wm.alloc_window_id();
+        wm.add_window(Window::new(c, "c")); // workspace 2, now globally most-recent
+
+        wm.switch_workspace(1);
+        let b = wm.alloc_window_id();
+        wm.add_window(Window::new(b, "b")); // workspace 1, now focused and globally most-recent
+
+        assert_eq!(wm.current_workspace(), 1);
+        wm.remove_window(b);
+        // The naive "global most recent" fallback would have landed on `c`
+        // (workspace 2) here - `a`, still on the workspace the user is
+        // actually looking at, is what a real desktop would land on.
+        assert_eq!(wm.focused_id(), Some(a));
+        assert_eq!(wm.current_workspace(), 1, "must not have been dragged onto workspace 2 by the fallback");
+    }
+
+    #[test]
+    fn closing_the_last_window_on_a_workspace_leaves_focus_none_by_default() {
+        let mut wm = wm_with_monitor();
+        assert!(!wm.close_focus_follows_workspace, "default must be off, matching every mainstream desktop");
+        let a = wm.alloc_window_id();
+        wm.add_window(Window::new(a, "a")); // workspace 1
+
+        let ws2 = wm.add_workspace("2", "dynamic");
+        wm.switch_workspace(ws2);
+        let c = wm.alloc_window_id();
+        wm.add_window(Window::new(c, "c")); // workspace 2
+
+        wm.switch_workspace(1);
+        wm.focus_window(a); // re-focus `a`; current_workspace stays 1 (already there)
+        assert_eq!(wm.current_workspace(), 1);
+
+        wm.remove_window(a);
+        // No window left on workspace 1 at all - with the setting off,
+        // this must not silently jump the user over to `c` on workspace 2.
+        assert_eq!(wm.focused_id(), None);
+        assert_eq!(wm.current_workspace(), 1);
+    }
+
+    #[test]
+    fn closing_the_last_window_on_a_workspace_can_still_follow_when_opted_in() {
+        let mut wm = wm_with_monitor();
+        wm.close_focus_follows_workspace = true;
+        let a = wm.alloc_window_id();
+        wm.add_window(Window::new(a, "a")); // workspace 1
+
+        let ws2 = wm.add_workspace("2", "dynamic");
+        wm.switch_workspace(ws2);
+        let c = wm.alloc_window_id();
+        wm.add_window(Window::new(c, "c")); // workspace 2
+
+        wm.switch_workspace(1);
+        wm.focus_window(a);
+        wm.remove_window(a);
+        // Opted in: the old always-follow-the-global-fallback behaviour.
+        assert_eq!(wm.focused_id(), Some(c));
+    }
+
+    #[test]
     fn new_window_on_dynamic_workspace_uses_smart_placement() {
         let mut wm = wm_with_monitor();
         let id = wm.alloc_window_id();
diff --git a/crates/core/src/manager/windows.rs b/crates/core/src/manager/windows.rs
index f29d19a..3271dee 100644
--- a/crates/core/src/manager/windows.rs
+++ b/crates/core/src/manager/windows.rs
@@ -271,7 +271,24 @@ impl WindowManager {
     pub fn remove_window(&mut self, id: WindowId) -> Option<Window> {
         self.order.retain(|&w| w != id);
         if self.focused == Some(id) {
-            self.focused = self.order.last().copied();
+            // Prefer the most-recently-focused window still on *this*
+            // workspace - `self.order` tracks every window globally, not
+            // per-workspace, so its own `.last()` (the previous behaviour)
+            // could just as easily be a background window sitting on a
+            // workspace the user isn't even looking at. `focus_window`
+            // switches the active workspace to match whatever it's given
+            // (a real, separate, and correct feature for a deliberate
+            // `srd dispatch focus` from elsewhere) - so handing it a
+            // cross-workspace fallback here silently dragged the user's
+            // whole view along with it the moment they closed a window,
+            // reported live as "teleports me to previous workspace".
+            // `close_focus_follows_workspace` (default `false`, matching
+            // every mainstream desktop - none of them change your active
+            // workspace just because a window closed) restores that
+            // original always-follow behaviour for anyone who wants it.
+            let current = self.current_workspace;
+            let same_workspace = self.order.iter().rev().copied().find(|&w| self.windows.get(&w).is_some_and(|win| win.workspace == current));
+            self.focused = same_workspace.or_else(|| self.close_focus_follows_workspace.then(|| self.order.last().copied()).flatten());
         }
         let window = self.windows.remove(&id);
         // Remembers wherever this app's window actually ended up, not just