Don't resolve non-local -webkit-clip-path references as local

third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
  * copyright notice, this list of conditions and the following disclaimer
  * in the documentation and/or other materials provided with the
  * distribution.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 106 matching lines @@
         convertLengthOrAuto(state, *rect.bottom()),
         convertLengthOrAuto(state, *rect.left()));
 }
 
 PassRefPtr<ClipPathOperation> StyleBuilderConverter::convertClipPath(StyleResolverState& state, const CSSValue& value)
 {
     if (value.isBasicShapeValue())
         return ShapeClipPathOperation::create(basicShapeForValue(state, value));
     if (value.isURIValue()) {
         SVGURLReferenceResolver resolver(toCSSURIValue(value).value(), state.document());
+        // If the reference is non-local, then the fragment will remain as a
+        // null string, which makes the element lookup fail.
+        AtomicString fragmentIdentifier;
+        if (resolver.isLocal())
+            fragmentIdentifier = resolver.fragmentIdentifier();
         // TODO(fs): Doesn't work with forward or external SVG references (crbug.com/391604, crbug.com/109212, ...)
-        return ReferenceClipPathOperation::create(toCSSURIValue(value).value(), resolver.fragmentIdentifier());
+        return ReferenceClipPathOperation::create(toCSSURIValue(value).value(), fragmentIdentifier);
     }
     DCHECK(value.isPrimitiveValue() && toCSSPrimitiveValue(value).getValueID() == CSSValueNone);
     return nullptr;
 }
 
 FilterOperations StyleBuilderConverter::convertFilterOperations(StyleResolverState& state, const CSSValue& value)
 {
     return FilterOperationResolver::createFilterOperations(state, value);
 }
 
@@ skipping 934 matching lines @@
 
 PassRefPtr<StylePath> StyleBuilderConverter::convertPathOrNone(StyleResolverState& state, const CSSValue& value)
 {
     if (value.isPathValue())
         return toCSSPathValue(value).stylePath();
     ASSERT(value.isPrimitiveValue() && toCSSPrimitiveValue(value).getValueID() == CSSValueNone);
     return nullptr;
 }
 
 } // namespace blink