fix(web): thread jump hints no longer stick after a dictation paste (pingdotgg#8189)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

Author: t3dotgg

apps/web/src/shortcutModifierState.test.ts

@@ -110,4 +110,29 @@ describe("shortcutModifierState", () => {
       shiftKey: false,
     });
   });
+
+  it("ignores poisoned modifier flags on non-modifier keys", () => {
+    // A dictation paste (synthetic ⌘V) can leave the browser reporting
+    // metaKey=true on later real key events. Enter to submit must not
+    // re-mark ⌘ as held.
+    const state = shortcutModifierStateAfterKeyboardEvent(
+      emptyState(),
+      keyboardEventLike("keydown", { key: "Enter", metaKey: true }),
+    );
+    expect(state).toEqual(emptyState());
+  });
+
+  it("clears a held modifier when a non-modifier key reports it released", () => {
+    const heldMeta: ShortcutModifierState = {
+      metaKey: true,
+      ctrlKey: false,
+      altKey: false,
+      shiftKey: false,
+    };
+    const state = shortcutModifierStateAfterKeyboardEvent(
+      heldMeta,
+      keyboardEventLike("keydown", { key: "a", metaKey: false }),
+    );
+    expect(state).toEqual(emptyState());
+  });
 });

apps/web/src/shortcutModifierState.ts

@@ -33,7 +33,12 @@ export function useShortcutModifierState(): ShortcutModifierState {
     const onKeyboardEvent = (event: KeyboardEvent) => {
       setState((current) => shortcutModifierStateAfterKeyboardEvent(current, event));
     };
-    const onWindowBlur = () => {
+    // Dictation tools (Wispr Flow) paste with a synthetic ⌘V whose Meta keyup
+    // never reaches the page, so the tracked state stays "⌘ held" forever and
+    // the thread jump hints stick on screen. A paste is never jump intent, so
+    // treat it like a blur and reset. A physically held modifier re-registers
+    // on the next real key event.
+    const onResetEvent = () => {
       setState((current) =>
         areShortcutModifierStatesEqual(current, EMPTY_SHORTCUT_MODIFIER_STATE)
           ? current
@@ -43,11 +48,13 @@ export function useShortcutModifierState(): ShortcutModifierState {
 
     window.addEventListener("keydown", onKeyboardEvent, true);
     window.addEventListener("keyup", onKeyboardEvent, true);
-    window.addEventListener("blur", onWindowBlur);
+    window.addEventListener("paste", onResetEvent, true);
+    window.addEventListener("blur", onResetEvent);
     return () => {
       window.removeEventListener("keydown", onKeyboardEvent, true);
       window.removeEventListener("keyup", onKeyboardEvent, true);
-      window.removeEventListener("blur", onWindowBlur);
+      window.removeEventListener("paste", onResetEvent, true);
+      window.removeEventListener("blur", onResetEvent);
     };
   }, []);
 
@@ -84,11 +91,17 @@ export function shortcutModifierStateAfterKeyboardEvent(
       [normalizedModifierKey]: event.type === "keydown",
     };
   } else {
+    // Flags on non-modifier keys may only clear a bit, never set one. After a
+    // dictation tool's synthetic ⌘V (Wispr Flow), the browser can keep
+    // reporting metaKey=true on real key events (Enter to submit) until the
+    // user physically taps ⌘. Trusting that flag would mark ⌘ as held and
+    // stick the thread jump hints. Setting a bit requires a real modifier
+    // keydown, handled above.
     nextState = {
-      metaKey: event.metaKey,
-      ctrlKey: event.ctrlKey,
-      altKey: event.altKey,
-      shiftKey: event.shiftKey,
+      metaKey: currentState.metaKey && event.metaKey,
+      ctrlKey: currentState.ctrlKey && event.ctrlKey,
+      altKey: currentState.altKey && event.altKey,
+      shiftKey: currentState.shiftKey && event.shiftKey,
     };
   }