From 704cc228a5f6456b15d5c29d18c9eefe1b0cf83f Mon Sep 17 00:00:00 2001
From: Jeff Chang <chengjeff@google.com>
Date: Thu, 19 Mar 2020 21:28:25 +0800
Subject: [PATCH] Fix the IntentTests test case failed

NPE occurs when process the pending reparent activities on
ResetTargetTaskHelper. Activities that enable the
allowTaskReparenting were not reparented to other tasks
while an activity was started with RESET_TASK_IF_NEEDED
flag.

This CL refactor the reparent path to fix the NPE.

Bug: 150303302
Test: atest CtsWindowManagerDeviceTestCases:IntentTests
Change-Id: I55f4eed0e6be8a2f59757fe9308b726196a1f011
---
 .../server/wm/ResetTargetTaskHelper.java      | 59 ++++++++-----------
 1 file changed, 26 insertions(+), 33 deletions(-)

diff --git a/services/core/java/com/android/server/wm/ResetTargetTaskHelper.java b/services/core/java/com/android/server/wm/ResetTargetTaskHelper.java
index 45f8a15979f4c..420997a5b82da 100644
--- a/services/core/java/com/android/server/wm/ResetTargetTaskHelper.java
+++ b/services/core/java/com/android/server/wm/ResetTargetTaskHelper.java
@@ -20,7 +20,6 @@ import static com.android.server.wm.ActivityStack.TAG_ADD_REMOVE;
 import static com.android.server.wm.ActivityStack.TAG_TASKS;
 import static com.android.server.wm.ActivityTaskManagerDebugConfig.DEBUG_ADD_REMOVE;
 import static com.android.server.wm.ActivityTaskManagerDebugConfig.DEBUG_TASKS;
-import static com.android.server.wm.Task.REPARENT_LEAVE_STACK_IN_PLACE;
 
 import android.app.ActivityOptions;
 import android.content.Intent;
@@ -233,29 +232,6 @@ class ResetTargetTaskHelper {
         }
 
         final ActivityTaskManagerService atmService = mTargetStack.mAtmService;
-        final ArrayList<Task> createdTasks = new ArrayList<>();
-        while (!mPendingReparentActivities.isEmpty()) {
-            final ActivityRecord r = mPendingReparentActivities.remove(0);
-            final ActivityRecord bottom = mTargetStack.getBottomMostActivity();
-            final Task targetTask;
-            if (bottom != null && r.taskAffinity.equals(bottom.getTask().affinity)) {
-                // If the activity currently at the bottom has the same task affinity as
-                // the one we are moving, then merge it into the same task.
-                targetTask = bottom.getTask();
-                if (DEBUG_TASKS) Slog.v(TAG_TASKS, "Start pushing activity "
-                        + r + " out to bottom task " + targetTask);
-            } else {
-                targetTask = mTargetStack.reuseOrCreateTask(
-                        r.info, null /*intent*/, false /*toTop*/);
-                targetTask.affinityIntent = r.intent;
-                createdTasks.add(targetTask);
-                if (DEBUG_TASKS) Slog.v(TAG_TASKS, "Start pushing activity "
-                        + r + " out to new task " + targetTask);
-            }
-            r.reparent(targetTask, 0 /* position */, "resetTargetTaskIfNeeded");
-            atmService.mStackSupervisor.mRecentTasks.add(targetTask);
-        }
-
         DisplayContent display = mTargetStack.getDisplay();
         final boolean singleTaskInstanceDisplay = display.isSingleTaskInstance();
         if (singleTaskInstanceDisplay) {
@@ -264,16 +240,33 @@ class ResetTargetTaskHelper {
 
         final int windowingMode = mTargetStack.getWindowingMode();
         final int activityType = mTargetStack.getActivityType();
-        if (!singleTaskInstanceDisplay && !display.alwaysCreateStack(windowingMode, activityType)) {
-            return;
-        }
 
-        while (!createdTasks.isEmpty()) {
-            final Task targetTask = createdTasks.remove(createdTasks.size() - 1);
-            final ActivityStack targetStack = display.getOrCreateStack(
-                    windowingMode, activityType, false /* onTop */);
-            targetTask.reparent(targetStack, false /* toTop */, REPARENT_LEAVE_STACK_IN_PLACE,
-                    false /* animate */, true /* deferResume */, "resetTargetTask");
+        while (!mPendingReparentActivities.isEmpty()) {
+            final ActivityRecord r = mPendingReparentActivities.remove(0);
+            final boolean alwaysCreateTask = DisplayContent.alwaysCreateStack(windowingMode,
+                    activityType);
+            final Task task = alwaysCreateTask
+                    ? display.getBottomMostTask() : mTargetStack.getBottomMostTask();
+            Task targetTask = null;
+            if (task != null && r.taskAffinity.equals(task.affinity)) {
+                // If the activity currently at the bottom has the same task affinity as
+                // the one we are moving, then merge it into the same task.
+                targetTask = task;
+                if (DEBUG_TASKS) Slog.v(TAG_TASKS, "Start pushing activity "
+                        + r + " out to bottom task " + targetTask);
+            }
+            if (targetTask == null) {
+                if (alwaysCreateTask) {
+                    targetTask = display.getOrCreateStack(windowingMode, activityType,
+                            false /* onTop */);
+                } else {
+                    targetTask = mTargetStack.reuseOrCreateTask(r.info, null /*intent*/,
+                            false /*toTop*/);
+                }
+                targetTask.affinityIntent = r.intent;
+            }
+            r.reparent(targetTask, 0 /* position */, "resetTargetTaskIfNeeded");
+            atmService.mStackSupervisor.mRecentTasks.add(targetTask);
         }
     }