surfaceflinger: Add check for number of queued buffers

Pop buffer item from shadow queue only when
number of queued buffer items is greater than zero.

Change-Id: I039bc133842293c29e3e130efd65f521ef0049c6
CRs-Fixed: 1009466

1 files changed, 6 insertions, 1 deletions

diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 3e932df..6a9cdb7 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -1448,11 +1448,16 @@ Region Layer::latchBuffer(bool& recomputeVisibleRegions)
 
             // Remove any stale buffers that have been dropped during
             // updateTexImage
-            while (mQueueItems[0].mFrameNumber != currentFrameNumber) {
+            while ((mQueuedFrames > 0) && (mQueueItems[0].mFrameNumber != currentFrameNumber)) {
                 mQueueItems.removeAt(0);
                 android_atomic_dec(&mQueuedFrames);
             }
 
+            if (mQueuedFrames == 0) {
+                ALOGE("[%s] mQueuedFrames is zero !!", mName.string());
+                return outDirtyRegion;
+            }
+
             mQueueItems.removeAt(0);
         }