If the rootTaskIdsToRestore is empty...

on user switch, restore the home task to the top for the user. This
happens when the home task belongs to the system user and is visible to
a secondary user.

Test: atest RootWindowContainerTest & manual
Bug: 391501236
Flag: com.android.window.flags.enable_top_visible_root_task_per_user_tracking
Change-Id: I345dc1b965cc21e5cbb12a6ee4dade79927eb696

1 files changed, 3 insertions, 6 deletions

diff --git a/services/core/java/com/android/server/wm/RootWindowContainer.java b/services/core/java/com/android/server/wm/RootWindowContainer.java
index cf464c707ff4..1fe6ad68a313 100644
--- a/services/core/java/com/android/server/wm/RootWindowContainer.java
+++ b/services/core/java/com/android/server/wm/RootWindowContainer.java
@@ -1948,7 +1948,7 @@ class RootWindowContainer extends WindowContainer<DisplayContent>
         final IntArray rootTaskIdsToRestore = mUserVisibleRootTasks.get(userId);
         boolean homeInFront = false;
         if (Flags.enableTopVisibleRootTaskPerUserTracking()) {
-            if (rootTaskIdsToRestore == null) {
+            if (rootTaskIdsToRestore == null || rootTaskIdsToRestore.size() == 0) {
                 // If there are no root tasks saved, try restore id 0 which should create and launch
                 // the home task.
                 handleRootTaskLaunchOnUserSwitch(/* restoreRootTaskId */INVALID_TASK_ID);
@@ -1958,11 +1958,8 @@ class RootWindowContainer extends WindowContainer<DisplayContent>
                     handleRootTaskLaunchOnUserSwitch(rootTaskIdsToRestore.get(i));
                 }
                 // Check if the top task is type home
-                if (rootTaskIdsToRestore.size() > 0) {
-                    final int topRootTaskId = rootTaskIdsToRestore.get(
-                            rootTaskIdsToRestore.size() - 1);
-                    homeInFront = isHomeTask(topRootTaskId);
-                }
+                final int topRootTaskId = rootTaskIdsToRestore.get(rootTaskIdsToRestore.size() - 1);
+                homeInFront = isHomeTask(topRootTaskId);
             }
         } else {
             handleRootTaskLaunchOnUserSwitch(restoreRootTaskId);