From 63b8ee365d1be3df6e340f94eea05eb59a8e76d8 Mon Sep 17 00:00:00 2001
From: Shunta Sato <Shunta.Sato@sonymobile.com>
Date: Mon, 11 Jul 2016 13:32:52 +0900
Subject: [PATCH] Return to Home stack when a context of tasks launched from
 Home finished

When the following conditions happen together, another context in
Application stack was launched unexpectedly:
- There is a context of tasks in Application stack, which is launched
  from a task on Home stack.
- All tasks/activities in the context are finishing.

Solution:
Add a condition check to see if the task is NOT one of the task
finishing on-top of the top running task.

Bug: 30883775
Test: manual
Author: Ichitaro Kohara <ichitaro.kohara@sonymobile.com>
Change-Id: I5d6097a7c8dc2733ff684957370c987dd158e329
---
 .../com/android/server/am/ActivityStack.java  | 23 ++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/services/core/java/com/android/server/am/ActivityStack.java b/services/core/java/com/android/server/am/ActivityStack.java
index f13b11e65a883..b9aa7ec79c544 100644
--- a/services/core/java/com/android/server/am/ActivityStack.java
+++ b/services/core/java/com/android/server/am/ActivityStack.java
@@ -3215,8 +3215,25 @@ class ActivityStack<T extends StackWindowController> extends ConfigurationContai
         r.addResultLocked(null, resultWho, requestCode, resultCode, data);
     }
 
+    /** Returns true if the task is one of the task finishing on-top of the top running task. */
+    boolean isATopFinishingTask(TaskRecord task) {
+        for (int i = mTaskHistory.size() - 1; i >= 0; --i) {
+            final TaskRecord current = mTaskHistory.get(i);
+            final ActivityRecord r = current.topRunningActivityLocked();
+            if (r != null) {
+                // We got a top running activity, so there isn't a top finishing task...
+                return false;
+            }
+            if (current == task) {
+                return true;
+            }
+        }
+        return false;
+    }
+
     private void adjustFocusedActivityStackLocked(ActivityRecord r, String reason) {
-        if (!mStackSupervisor.isFocusedStack(this) || mResumedActivity != r) {
+        if (!mStackSupervisor.isFocusedStack(this) ||
+                ((mResumedActivity != r) && (mResumedActivity != null))) {
             return;
         }
 
@@ -3231,8 +3248,8 @@ class ActivityStack<T extends StackWindowController> extends ConfigurationContai
                 final TaskRecord task = r.getTask();
                 final boolean isAssistantOrOverAssistant = task.getStack().isAssistantStack() ||
                         task.isOverAssistantStack();
-                if (r.frontOfTask && task == topTask() &&
-                        (task.isOverHomeStack() || isAssistantOrOverAssistant)) {
+                if (r.frontOfTask && isATopFinishingTask(task)
+                        && (task.isOverHomeStack() || isAssistantOrOverAssistant)) {
                     // For non-fullscreen or assistant stack, we want to move the focus to the next
                     // visible stack to prevent the home screen from moving to the top and obscuring
                     // other visible stacks.