From 0c4d81cf1350101687c5090b18c7a3c5bc1f348c Mon Sep 17 00:00:00 2001
From: Craig Mautner <cmautner@google.com>
Date: Tue, 20 Jan 2015 11:56:27 -0800
Subject: [PATCH] Do not defer removal for empty tasks or activities

It is possible for empty activities to be leaked if their last
window is removed before animations finish. This change keeps tasks
and activities from having removal deferred if they have no windows.

Fixes bug 19047432

Change-Id: If6562f46bbfcac9ba987e2c834a1d55a9a8f3766
---
 .../com/android/server/wm/WindowManagerService.java   | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index b9a2cbe02c8bb..1c2fbb1668f37 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -4810,7 +4810,7 @@ public class WindowManagerService extends IWindowManager.Stub
                 if (DEBUG_ADD_REMOVE || DEBUG_TOKEN_MOVEMENT) Slog.v(TAG, "removeAppToken: "
                         + wtoken + " delayed=" + delayed + " Callers=" + Debug.getCallers(4));
                 final TaskStack stack = mTaskIdToTask.get(wtoken.groupId).mStack;
-                if (delayed) {
+                if (delayed && !wtoken.allAppWindows.isEmpty()) {
                     // set the token aside because it has an active animation to be finished
                     if (DEBUG_ADD_REMOVE || DEBUG_TOKEN_MOVEMENT) Slog.v(TAG,
                             "removeAppToken make exiting: " + wtoken);
@@ -5194,7 +5194,7 @@ public class WindowManagerService extends IWindowManager.Stub
     void removeTaskLocked(Task task) {
         final int taskId = task.taskId;
         final TaskStack stack = task.mStack;
-        if (stack.isAnimating()) {
+        if (!task.mAppTokens.isEmpty() && stack.isAnimating()) {
             if (DEBUG_STACK) Slog.i(TAG, "removeTask: deferring removing taskId=" + taskId);
             task.mDeferRemoval = true;
             return;
@@ -10041,7 +10041,8 @@ public class WindowManagerService extends IWindowManager.Stub
                     mStackIdToStack.valueAt(stackNdx).mExitingAppTokens;
             for (i = exitingAppTokens.size() - 1; i >= 0; i--) {
                 AppWindowToken token = exitingAppTokens.get(i);
-                if (!token.hasVisible && !mClosingApps.contains(token) && !token.mDeferRemoval) {
+                if (!token.hasVisible && !mClosingApps.contains(token) &&
+                        (!token.mDeferRemoval || token.allAppWindows.isEmpty())) {
                     // Make sure there is no animation running on this token,
                     // so any windows associated with it will be removed as
                     // soon as their animations are complete
@@ -10051,6 +10052,10 @@ public class WindowManagerService extends IWindowManager.Stub
                             "performLayout: App token exiting now removed" + token);
                     removeAppFromTaskLocked(token);
                     exitingAppTokens.remove(i);
+                    final Task task = mTaskIdToTask.get(token.groupId);
+                    if (task != null && task.mDeferRemoval && task.mAppTokens.isEmpty()) {
+                        removeTaskLocked(task);
+                    }
                 }
             }
         }