commit 828d7ca895fc412ed12f2644ceb465bc03922470
author Riddle Hsu <riddlehsu@google.com> Sat Jun 11 00:22:33 2022 +0800
committer Riddle Hsu <riddlehsu@google.com> Sat Jun 11 00:22:33 2022 +0800
tree 4490ca62ba4b783101a098519f22cb80cfcfa329
parent 51d1c6ec661550a6b7033aaf42c378f866cf9cc5

Avoid potential NPE if the restore-below task is not collected

If there is an existing collecting transition, the restore-below
task may not be collected.

Also make sure continueWindowLayout() will be called in finally
block. Previously if handleStartResult() throws exception, the
surface layout will be broken that its defer count isn't paired.

Bug: 230582311
Test: adb shell setprop persist.wm.debug.shell_transit 1; reboot
      Launch/swipe app quickly many times.
Change-Id: I7ae962c5085630a5cf194625d2f8b3e8f30a45b2

services/core/java/com/android/server/wm/ActivityStarter.java

diff --git a/services/core/java/com/android/server/wm/ActivityStarter.java b/services/core/java/com/android/server/wm/ActivityStarter.java
index 3bf1c51..fc412cbd 100644
--- a/services/core/java/com/android/server/wm/ActivityStarter.java
+++ b/services/core/java/com/android/server/wm/ActivityStarter.java
@@ -1660,14 +1660,17 @@
         transitionController.collect(r);
         try {
             mService.deferWindowLayout();
-            Trace.traceBegin(Trace.TRACE_TAG_WINDOW_MANAGER, "startActivityInner");
-            result = startActivityInner(r, sourceRecord, voiceSession, voiceInteractor,
-                    startFlags, doResume, options, inTask, inTaskFragment, restrictedBgActivity,
-                    intentGrants);
+            try {
+                Trace.traceBegin(Trace.TRACE_TAG_WINDOW_MANAGER, "startActivityInner");
+                result = startActivityInner(r, sourceRecord, voiceSession, voiceInteractor,
+                        startFlags, doResume, options, inTask, inTaskFragment, restrictedBgActivity,
+                        intentGrants);
+            } finally {
+                Trace.traceEnd(Trace.TRACE_TAG_WINDOW_MANAGER);
+                startedActivityRootTask = handleStartResult(r, options, result, newTransition,
+                        remoteTransition);
+            }
         } finally {
-            Trace.traceEnd(Trace.TRACE_TAG_WINDOW_MANAGER);
-            startedActivityRootTask = handleStartResult(r, options, result, newTransition,
-                    remoteTransition);
             mService.continueWindowLayout();
         }
         postStartActivityProcessing(r, result, startedActivityRootTask);

services/core/java/com/android/server/wm/Transition.java

diff --git a/services/core/java/com/android/server/wm/Transition.java b/services/core/java/com/android/server/wm/Transition.java
index f163050..d8404a7 100644
--- a/services/core/java/com/android/server/wm/Transition.java
+++ b/services/core/java/com/android/server/wm/Transition.java
@@ -229,7 +229,9 @@
 
         if (restoreBelow != null) {
             final ChangeInfo info = mChanges.get(restoreBelow);
-            info.mFlags |= ChangeInfo.FLAG_ABOVE_TRANSIENT_LAUNCH;
+            if (info != null) {
+                info.mFlags |= ChangeInfo.FLAG_ABOVE_TRANSIENT_LAUNCH;
+            }
         }
         ProtoLog.v(ProtoLogGroup.WM_DEBUG_WINDOW_TRANSITIONS, "Transition %d: Set %s as "
                 + "transient-launch", mSyncId, activity);