commit 7d701174f423754a2dade39fd16f102c085bd865
author Wale Ogunwale <ogunwale@google.com> Wed Mar 11 15:36:30 2015 -0700
committer Wale Ogunwale <ogunwale@google.com> Thu Mar 12 15:03:22 2015 -0700
tree 9f17d8c6daa09c1e2c1ac06d582fa0fc95389bcc
parent 04f4d6bb8892fe9b6e8f60d18a4f4dd051ab8124

Protect against NPE for ActivityRecords without a stack.

A previous change allowed us to remove stack that no longer contained
any task. This was causing some NPE when an ActivityRecord.Token or
some other cached ActivityRecord later gets converted back to an
ActivityRecord and we try to access its stack.

Bug: 19552874
Change-Id: Ie9454bbce56591b337f97af40f8c00b8597becdf

services/core/java/com/android/server/am/ActivityStack.java

diff --git a/services/core/java/com/android/server/am/ActivityStack.java b/services/core/java/com/android/server/am/ActivityStack.java
index 43d297f..b8e59ac 100644
--- a/services/core/java/com/android/server/am/ActivityStack.java
+++ b/services/core/java/com/android/server/am/ActivityStack.java
@@ -461,7 +461,7 @@
     }
 
     ActivityRecord isInStackLocked(IBinder token) {
-        final ActivityRecord r = ActivityRecord.forToken(token);
+        final ActivityRecord r = ActivityRecord.forTokenLocked(token);
         return isInStackLocked(r);
     }
 
@@ -470,7 +470,8 @@
             return null;
         }
         final TaskRecord task = r.task;
-        if (task != null && task.mActivities.contains(r) && mTaskHistory.contains(task)) {
+        if (task != null && task.stack != null
+                && task.mActivities.contains(r) && mTaskHistory.contains(task)) {
             if (task.stack != this) Slog.w(TAG,
                     "Illegal state! task does not point to stack it is in.");
             return r;
@@ -2795,7 +2796,7 @@
             return false;
         }
 
-        r.makeFinishing();
+        r.makeFinishingLocked();
         final TaskRecord task = r.task;
         EventLog.writeEvent(EventLogTags.AM_FINISH_ACTIVITY,
                 r.userId, System.identityHashCode(r),
@@ -2898,7 +2899,7 @@
                 || prevState == ActivityState.INITIALIZING) {
             // If this activity is already stopped, we can just finish
             // it right now.
-            r.makeFinishing();
+            r.makeFinishingLocked();
             boolean activityRemoved = destroyActivityLocked(r, true, "finish-imm");
             if (activityRemoved) {
                 mStackSupervisor.resumeTopActivitiesLocked();
@@ -2974,9 +2975,8 @@
         return false;
     }
 
-    final boolean navigateUpToLocked(IBinder token, Intent destIntent, int resultCode,
+    final boolean navigateUpToLocked(ActivityRecord srec, Intent destIntent, int resultCode,
             Intent resultData) {
-        final ActivityRecord srec = ActivityRecord.forToken(token);
         final TaskRecord task = srec.task;
         final ArrayList<ActivityRecord> activities = task.mActivities;
         final int start = activities.indexOf(srec);
@@ -3123,7 +3123,7 @@
     private void removeActivityFromHistoryLocked(ActivityRecord r, String reason) {
         mStackSupervisor.removeChildActivityContainers(r);
         finishActivityResultsLocked(r, Activity.RESULT_CANCELED, null);
-        r.makeFinishing();
+        r.makeFinishingLocked();
         if (DEBUG_ADD_REMOVE) {
             RuntimeException here = new RuntimeException("here");
             here.fillInStackTrace();
@@ -3364,7 +3364,7 @@
     final void activityDestroyedLocked(IBinder token, String reason) {
         final long origId = Binder.clearCallingIdentity();
         try {
-            ActivityRecord r = ActivityRecord.forToken(token);
+            ActivityRecord r = ActivityRecord.forTokenLocked(token);
             if (r != null) {
                 mHandler.removeMessages(DESTROY_TIMEOUT_MSG, r);
             }
@@ -3945,7 +3945,7 @@
                 }
             }
         }
-        final ActivityRecord r = ActivityRecord.forToken(token);
+        final ActivityRecord r = ActivityRecord.forTokenLocked(token);
         if (r == null) {
             return false;
         }