Fix null deref

Bug: 21857172

willHaveFunctor was assuming that either mStagingDisplayList
or mDisplayList would be non-null but this isn't true. Both
can be null in some scenarios (notably after a trimMemory)

Change-Id: Ia2915b84cfc907ec9c7cbec54ed6dc26283ec998

1 files changed, 6 insertions, 2 deletions

diff --git a/libs/hwui/RenderNode.cpp b/libs/hwui/RenderNode.cpp
index b4cbc3617cc5..fc184913e1c1 100644
--- a/libs/hwui/RenderNode.cpp
+++ b/libs/hwui/RenderNode.cpp
@@ -241,8 +241,12 @@ void RenderNode::prepareTreeImpl(TreeInfo& info, bool functorsNeedLayer) {
         animatorDirtyMask = mAnimatorManager.animate(info);
     }
 
-    bool willHaveFunctor = info.mode == TreeInfo::MODE_FULL && mStagingDisplayListData
-            ? !mStagingDisplayListData->functors.isEmpty() : !mDisplayListData->functors.isEmpty();
+    bool willHaveFunctor = false;
+    if (info.mode == TreeInfo::MODE_FULL && mStagingDisplayListData) {
+        willHaveFunctor = !mStagingDisplayListData->functors.isEmpty();
+    } else if (mDisplayListData) {
+        willHaveFunctor = !mDisplayListData->functors.isEmpty();
+    }
     bool childFunctorsNeedLayer = mProperties.prepareForFunctorPresence(
             willHaveFunctor, functorsNeedLayer);