#941: a hidden window drops its waiting key tip request

Addresses CodeRabbit review on #3250, "Clear deferred key-tip requests
when parking a hidden window": a hidden window isn't drawn, so a request
it parked would fire whenever it was shown again (the Symbol gallery
opening long after the keys). Parking a hidden window now drops it; the
rest of its interface state is kept.

Test: legacy_keytips::a_hidden_window_drops_its_waiting_key_tip_request.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/ui-egui/src/window_ui.rs

@@ -112,7 +112,12 @@ impl SheetApp {
         };
         let mut outgoing = WindowUi::fresh(&self.grid, &self.ui.ribbon_tab);
         self.swap_window_ui(&mut outgoing);
-        if self.session.window(previous).is_some() {
+        if let Some(window) = self.session.window(previous) {
+            // A hidden window isn't drawn: a key tip request waiting for its next frame would
+            // fire whenever it is shown again, so it goes.
+            if window.hidden {
+                outgoing.keytip_invoke_next = None;
+            }
             self.parked.insert(previous, outgoing);
         }
         if let Some(mut incoming) = active.and_then(|w| self.parked.remove(&w)) {

crates/ui-egui/tests/it/legacy_keytips.rs

@@ -69,3 +69,23 @@ fn a_waiting_key_tip_request_stays_with_its_window() {
     h.state_mut().show_window(second);
     assert_eq!(h.state().ui.keytip_invoke_next, Some("insert.symbol"));
 }
+
+#[test]
+fn a_hidden_window_drops_its_waiting_key_tip_request() {
+    // A hidden window isn't drawn, so its waiting request would fire when it was shown again,
+    // long after the keys: hiding the window drops it.
+    let mut s = Session::new();
+    s.new_workbook();
+    let mut h = crate::common::os_harness(s, OperatingSystem::Nix);
+    h.run_steps(2);
+    let first = h.state().session.active_window().unwrap();
+    h.state_mut().run("view.newWindow", json!({})).unwrap();
+    let second = h.state().session.active_window().unwrap();
+    h.state_mut().show_window(second);
+    h.state_mut().ui.keytip_invoke_next = Some("insert.symbol");
+    h.state_mut().run("view.hideWindow", json!({"window": second})).unwrap();
+    h.state_mut().show_window(first);
+    h.state_mut().run("view.unhideWindow", json!({"window": second})).unwrap();
+    h.state_mut().show_window(second);
+    assert_eq!(h.state().ui.keytip_invoke_next, None);
+}