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.

1 files changed, 66 insertions, 0 deletions

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();