fix(android): the sidebar opens threads while New thread is open

apps/mobile/src/features/workspace/AndroidWorkspaceNavigation.android.tsx

@@ -1,5 +1,5 @@
 import { requireNativeView } from "expo";
-import { CommonActions, useNavigation } from "@react-navigation/native";
+import { useNavigation } from "@react-navigation/native";
 import { androidWorkspaceNavigationState } from "../../lib/android-workspace-navigation";
 import {
   Keyboard,
@@ -16,6 +16,7 @@ import { androidWorkspaceNavigationColors } from "./android-workspace-navigation
 import { useAppearancePreferences } from "../settings/appearance/AppearancePreferencesProvider";
 import { useWorkspaceTabs } from "./WorkspaceTabsContext";
 import type { WorkspaceTab } from "./workspace-tabs-state";
+import { resetAndroidWorkspace } from "./useAndroidWorkspaceSelection";
 
 export const ANDROID_WORKSPACE_RAIL_WIDTH = 80;
 
@@ -81,9 +82,7 @@ export function AndroidWorkspaceNavigation(props: {
           const tab = event.nativeEvent.tab;
           if (tab !== workspace.state.selectedTab) {
             workspace.dispatch({ type: "select", tab });
-            navigation.dispatch((state) =>
-              CommonActions.reset(androidWorkspaceNavigationState(state)),
-            );
+            resetAndroidWorkspace(navigation, (state) => androidWorkspaceNavigationState(state));
           }
           props.onSelect?.();
         }}

apps/mobile/src/features/workspace/useAndroidWorkspaceSelection.ts

@@ -1,4 +1,9 @@
-import { CommonActions, useNavigation } from "@react-navigation/native";
+import {
+  CommonActions,
+  useNavigation,
+  type NavigationAction,
+  type NavigationState,
+} from "@react-navigation/native";
 import { useCallback } from "react";
 import { Keyboard } from "react-native";
 import {
@@ -7,6 +12,27 @@ import {
 } from "../../lib/android-workspace-navigation";
 import { useWorkspaceTabs } from "./WorkspaceTabsContext";
 
+/**
+ * The sidebar and navigation rail sit in the root layout, where a state-callback dispatch goes
+ * to the focused navigator. While a nested flow such as New thread has focus, that navigator has
+ * no Home or Thread route and drops the reset, so address the root stack by its key.
+ */
+interface WorkspaceNavigation {
+  getParent(): WorkspaceNavigation | undefined;
+  getState(): NavigationState | undefined;
+  dispatch(action: NavigationAction): void;
+}
+
+export function resetAndroidWorkspace(
+  navigation: WorkspaceNavigation,
+  next: (state: NavigationState) => Parameters<typeof CommonActions.reset>[0],
+) {
+  let root = navigation;
+  for (let parent = root.getParent(); parent; parent = parent.getParent()) root = parent;
+  const state = root.getState();
+  if (state) root.dispatch({ ...CommonActions.reset(next(state)), target: state.key });
+}
+
 export function useAndroidWorkspaceSelection() {
   const navigation = useNavigation();
   const dispatch = useWorkspaceTabs()?.dispatch;
@@ -20,8 +46,8 @@ export function useAndroidWorkspaceSelection() {
         type: "select",
         tab: destination.name === "Thread" ? "threads" : "pullRequests",
       });
-      navigation.dispatch((state) =>
-        CommonActions.reset(androidWorkspaceNavigationState(state, destination, reviewers)),
+      resetAndroidWorkspace(navigation, (state) =>
+        androidWorkspaceNavigationState(state, destination, reviewers),
       );
     },
     [navigation, dispatch],