check for zero conic weights in interp

src/core/SkPath.cpp

Index: src/core/SkPath.cpp
diff --git a/src/core/SkPath.cpp b/src/core/SkPath.cpp
index 10e80a47a33804476650c6a99c9d0248a609f94a..06bbeef096ba9734cb0a733c7d9b983893ad658a 100644
--- a/src/core/SkPath.cpp
+++ b/src/core/SkPath.cpp
@@ -205,7 +205,8 @@ bool SkPath::isInterpolatable(const SkPath& compare) const {
                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())));
 }