Check for NULL texture in GrAutoScratchTexture::detach()

include/gpu/GrContext.h

 
 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef GrContext_DEFINED
@@ skipping 960 matching lines @@
      * "locked" in the texture cache until it is freed and recycled in
      * GrTexture::internal_dispose. In reality, the texture has been removed
      * from the cache (because this is in AutoScratchTexture) and by not
      * calling unlockScratchTexture we simply don't re-add it. It will be
      * reattached in GrTexture::internal_dispose.
      *
      * Note that the caller is assumed to accept and manage the ref to the
      * returned texture.
      */
     GrTexture* detach() {
+        if (NULL == fTexture) {
+            return NULL;
+        }
         GrTexture* texture = fTexture;
         fTexture = NULL;
 
         // This GrAutoScratchTexture has a ref from lockAndRefScratchTexture, which we give up now.
         // The cache also has a ref which we are lending to the caller of detach(). When the caller
         // lets go of the ref and the ref count goes to 0 internal_dispose will see this flag is
         // set and re-ref the texture, thereby restoring the cache's ref.
         GrAssert(texture->getRefCnt() > 1);
         texture->setFlag((GrTextureFlags) GrTexture::kReturnToCache_FlagBit);
         texture->unref();
@@ skipping 20 matching lines @@
     }
 
     GrTexture* texture() { return fTexture; }
 
 private:
     GrContext*                    fContext;
     GrTexture*                    fTexture;
 };
 
 #endif