handle null vertex or index buffers in batch

BUG=skia:

Review URL: https://codereview.chromium.org/979343002

1 files changed, 5 insertions, 0 deletions

diff --git a/gm/convexpolyeffect.cpp b/gm/convexpolyeffect.cpp
index 0a3be28c73..f3335c94e5 100644
--- a/gm/convexpolyeffect.cpp
+++ b/gm/convexpolyeffect.cpp
@@ -62,6 +62,11 @@ private:
                                                               &vertexBuffer,
                                                               &firstVertex);
 
+        if (!vertices || !batchTarget->quadIndexBuffer()) {
+            SkDebugf("Could not allocate buffers\n");
+            return;
+        }
+
         SkASSERT(vertexStride == sizeof(SkPoint));
         SkPoint* verts = reinterpret_cast<SkPoint*>(vertices);