check for zero conic weights in interp

src/core/SkPath.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBuffer.h"
 #include "SkCubicClipper.h"
 #include "SkErrorInternals.h"
@@ skipping 187 matching lines @@
     if (count != compare.fPathRef->countVerbs()) {
         return false;
     }
     if (!count) {
         return true;
     }
     if (memcmp(fPathRef->verbsMemBegin(), compare.fPathRef->verbsMemBegin(),
                count)) {
         return false;
     }
-    return !SkToBool(memcmp(fPathRef->conicWeights(), compare.fPathRef->conicWeights(),
+    return !fPathRef->countWeights() ||
+            !SkToBool(memcmp(fPathRef->conicWeights(), compare.fPathRef->conicWeights(),
             fPathRef->countWeights() * sizeof(*fPathRef->conicWeights())));
 }
 
 bool SkPath::interpolate(const SkPath& ending, SkScalar weight, SkPath* out) const {
     int verbCount = fPathRef->countVerbs();
     if (verbCount != ending.fPathRef->countVerbs()) {
         return false;
     }
     if (!verbCount) {
         return true;
@@ skipping 2990 matching lines @@
         }
     } while (!done);
     return SkToBool(tangents.count()) ^ isInverse;
 }
 
 int SkPath::ConvertConicToQuads(const SkPoint& p0, const SkPoint& p1, const SkPoint& p2,
                                 SkScalar w, SkPoint pts[], int pow2) {
     const SkConic conic(p0, p1, p2, w);
     return conic.chopIntoQuadsPOW2(pts, pow2);
 }