Fix a crash on stroking empty paths with nv_path_rendering enabled

src/gpu/GrContext.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrContext.h"
 
 #include "effects/GrSingleTextureEffect.h"
 #include "effects/GrConfigConversionEffect.h"
 
 #include "GrBufferAllocPool.h"
 #include "GrGpu.h"
 #include "GrDrawTargetCaps.h"
 #include "GrIndexBuffer.h"
 #include "GrInOrderDrawBuffer.h"
 #include "GrOvalRenderer.h"
 #include "GrPathRenderer.h"
 #include "GrPathUtils.h"
 #include "GrResourceCache.h"
 #include "GrSoftwarePathRenderer.h"
 #include "GrStencilBuffer.h"
 #include "GrTextStrike.h"
 #include "SkRTConf.h"
+#include "SkRRect.h"
 #include "SkStrokeRec.h"
 #include "SkTLazy.h"
 #include "SkTLS.h"
 #include "SkTrace.h"
 
 SK_DEFINE_INST_COUNT(GrContext)
 SK_DEFINE_INST_COUNT(GrDrawState)
 
 // It can be useful to set this to false to test whether a bug is caused by using the
 // InOrderDrawBuffer, to compare performance of using/not using InOrderDrawBuffer, or to make
@@ skipping 907 matching lines @@
     } else {
         target->drawNonIndexed(primitiveType, 0, vertexCount);
     }
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 void GrContext::drawRRect(const GrPaint& paint,
                           const SkRRect& rect,
                           const SkStrokeRec& stroke) {
+    if (rect.isEmpty()) {
+       return;
+    }
 
     AutoRestoreEffects are;
     GrDrawTarget* target = this->prepareToDraw(&paint, BUFFERED_DRAW, &are);
 
     bool useAA = paint.isAntiAlias() &&
                  !target->getDrawState().getRenderTarget()->isMultisampled() &&
                  !disable_coverage_aa_for_blend(target);
 
     if (!fOvalRenderer->drawSimpleRRect(target, this, useAA, rect, stroke)) {
         SkPath path;
         path.addRRect(rect);
         this->internalDrawPath(target, useAA, path, stroke);
     }
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 void GrContext::drawOval(const GrPaint& paint,
                          const SkRect& oval,
                          const SkStrokeRec& stroke) {
+    if (oval.isEmpty()) {
+       return;
+    }
 
     AutoRestoreEffects are;
     GrDrawTarget* target = this->prepareToDraw(&paint, BUFFERED_DRAW, &are);
 
     bool useAA = paint.isAntiAlias() &&
                  !target->getDrawState().getRenderTarget()->isMultisampled() &&
                  !disable_coverage_aa_for_blend(target);
 
     if (!fOvalRenderer->drawOval(target, this, useAA, oval, stroke)) {
         SkPath path;
@@ skipping 90 matching lines @@
     bool isOval = path.isOval(&ovalRect);
 
     if (!isOval || path.isInverseFillType()
         || !fOvalRenderer->drawOval(target, this, useAA, ovalRect, stroke)) {
         this->internalDrawPath(target, useAA, path, stroke);
     }
 }
 
 void GrContext::internalDrawPath(GrDrawTarget* target, bool useAA, const SkPath& path,
                                  const SkStrokeRec& stroke) {
+    SkASSERT(!path.isEmpty());
 
     // An Assumption here is that path renderer would use some form of tweaking
     // the src color (either the input alpha or in the frag shader) to implement
     // aa. If we have some future driver-mojo path AA that can do the right
     // thing WRT to the blend then we'll need some query on the PR.
     if (disable_coverage_aa_for_blend(target)) {
 #if GR_DEBUG
         //GrPrintf("Turning off AA to correctly apply blend.\n");
 #endif
         useAA = false;
@@ skipping 10 matching lines @@
     GrPathRenderer* pr = this->getPathRenderer(*pathPtr, strokeRec, target, false, type);
 
     if (NULL == pr) {
         if (!strokeRec.isHairlineStyle()) {
             // It didn't work the 1st time, so try again with the stroked path
             if (strokeRec.applyToPath(&tmpPath, *pathPtr)) {
                 pathPtr = &tmpPath;
                 strokeRec.setFillStyle();
             }
         }
+        if (pathPtr->isEmpty()) {
+            return;
+        }
+
         // This time, allow SW renderer
         pr = this->getPathRenderer(*pathPtr, strokeRec, target, true, type);
     }
 
     if (NULL == pr) {
 #if GR_DEBUG
         GrPrintf("Unable to find path renderer compatible with path.\n");
 #endif
         return;
     }
@@ skipping 580 matching lines @@
         return NULL;
     }
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 #if GR_CACHE_STATS
 void GrContext::printCacheStats() const {
     fTextureCache->printStats();
 }
 #endif