Clip scissor to RT bounds

src/gpu/GrClipMaskManager.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrClipMaskManager.h"
 #include "GrAAConvexPathRenderer.h"
 #include "GrAAHairLinePathRenderer.h"
@@ skipping 222 matching lines @@
         this->setPipelineBuilderStencil(pipelineBuilder, ars);
         return true;
     }
 
     // The clip mask manager always draws with a single IRect so we special case that logic here
     // Image filters just use a rect, so we also special case that logic
     switch (clip.clipType()) {
         case GrClip::kWideOpen_ClipType:
             SkFAIL("Should have caught this with clip.isWideOpen()");
             return true;
-        case GrClip::kIRect_ClipType:
-            scissorState->set(clip.irect());
-            this->setPipelineBuilderStencil(pipelineBuilder, ars);
-            return true;
+        case GrClip::kIRect_ClipType: {
+            SkIRect scissor = clip.irect();
+            if (scissor.intersect(clipSpaceRTIBounds)) {
+                scissorState->set(scissor);
+                this->setPipelineBuilderStencil(pipelineBuilder, ars);
+                return true;
+            }
+            return false;
+        }
         case GrClip::kClipStack_ClipType: {
             clipSpaceRTIBounds.offset(clip.origin());
             GrReducedClip::ReduceClipStack(*clip.clipStack(),
                                             clipSpaceRTIBounds,
                                             &elements,
                                             &genID,
                                             &initialState,
                                             &clipSpaceIBounds,
                                             &requiresAA);
             if (elements.isEmpty()) {
@@ skipping 851 matching lines @@
     fAACache.setContext(clipTarget->getContext());
 }
 
 void GrClipMaskManager::adjustPathStencilParams(const GrStencilBuffer* stencilBuffer,
                                                 GrStencilSettings* settings) {
     if (stencilBuffer) {
         int stencilBits = stencilBuffer->bits();
         this->adjustStencilParams(settings, fClipMode, stencilBits);
     }
 }