From c24078f1a2500dd7227b8be556999968ba51c24b Mon Sep 17 00:00:00 2001
From: Robert Carr <racarr@google.com>
Date: Thu, 11 Aug 2016 13:03:02 -0700
Subject: [PATCH] Fix NPE in deferToPendingTransaction.

Just because a child window has a surface doesn't necessarily
mean the parent window will have a surface. destroySurfaceLocked()
only takes care of setting mAttachedHidden so the child surface
will be invisible, but it may not be destroyed until a later point.

Bug: 30813094
Change-Id: Idb1b03fd61a7537ebfe33bafc93f278c0e6751f4
---
 .../core/java/com/android/server/wm/WindowStateAnimator.java   | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/services/core/java/com/android/server/wm/WindowStateAnimator.java b/services/core/java/com/android/server/wm/WindowStateAnimator.java
index e374ee91389f5..351961a8736a9 100644
--- a/services/core/java/com/android/server/wm/WindowStateAnimator.java
+++ b/services/core/java/com/android/server/wm/WindowStateAnimator.java
@@ -2066,7 +2066,8 @@ class WindowStateAnimator {
         if (time > mDeferTransactionTime + PENDING_TRANSACTION_FINISH_WAIT_TIME) {
             mDeferTransactionTime = -1;
             mDeferTransactionUntilFrame = -1;
-        } else {
+        } else if (mWin.mAttachedWindow != null &&
+                mWin.mAttachedWindow.mWinAnimator.hasSurface()) {
             mSurfaceController.deferTransactionUntil(
                     mWin.mAttachedWindow.mWinAnimator.mSurfaceController.getHandle(),
                     mDeferTransactionUntilFrame);