Avoid NPE around mReusedTask of ActivityStarter

Symptom:
System crash by NPE is observed on ActivityStarter
during phone boot-up.

Detail and sample:
ActivityStarter has possibility to be called itself recursively
by calling TaskRecord$performClearTaskLocked().
Then class variable of mReusedTask is initialized to null
after the call, because the recursive call isn't guarded by
synchronized block.
Then NPE crash occurs on next statement.

Solutions:
Call performClearTaskLocked() before assigning 
intentActivity.task to mReusedTask.

Bug: 32361138
Test: builds, boots, Manual testing of condition in bug
Author: Shigeki Yokomichi <shigeki.x.yokomichi@sonymobile.com>
Change-Id: Iaea3e066a6f7134fcae4338ff864bb236241194c
(cherry picked from commit 0bd28e2c5f)
This commit is contained in:
Shunta Sato
2016-10-12 18:35:17 +09:00
committed by Andrii Kulian
parent 33db4b77d5
commit 9fff53f2cb

View File

@@ -1623,9 +1623,9 @@ class ActivityStarter {
== (FLAG_ACTIVITY_NEW_TASK | FLAG_ACTIVITY_CLEAR_TASK)) { == (FLAG_ACTIVITY_NEW_TASK | FLAG_ACTIVITY_CLEAR_TASK)) {
// The caller has requested to completely replace any existing task with its new // The caller has requested to completely replace any existing task with its new
// activity. Well that should not be too hard... // activity. Well that should not be too hard...
intentActivity.task.performClearTaskLocked();
intentActivity.task.setIntent(mStartActivity);
mReuseTask = intentActivity.task; mReuseTask = intentActivity.task;
mReuseTask.performClearTaskLocked();
mReuseTask.setIntent(mStartActivity);
// When we clear the task - focus will be adjusted, which will bring another task // When we clear the task - focus will be adjusted, which will bring another task
// to top before we launch the activity we need. This will temporary swap their // to top before we launch the activity we need. This will temporary swap their
// mTaskToReturnTo values and we don't want to overwrite them accidentally. // mTaskToReturnTo values and we don't want to overwrite them accidentally.