ASSERTION FAILED: !m_parsedCalculation in CSSPropertyParser::parseCalculation

Source/core/css/parser/CSSPropertyParser.cpp

Index: Source/core/css/parser/CSSPropertyParser.cpp
diff --git a/Source/core/css/parser/CSSPropertyParser.cpp b/Source/core/css/parser/CSSPropertyParser.cpp
index e70d834aea288bd5d0871a543bff547ab6db5068..0a0e8f882f394f527c1e10c5d50b456080c65f83 100644
--- a/Source/core/css/parser/CSSPropertyParser.cpp
+++ b/Source/core/css/parser/CSSPropertyParser.cpp
@@ -5551,7 +5551,7 @@ PassRefPtrWillBeRawPtr<CSSValueList> CSSPropertyParser::parseShadow(CSSParserVal
                 return nullptr;
 
             // Blur radius must be non-negative.
-            if (context.allowBlur && !validUnit(val, FLength | FNonNeg, HTMLStandardMode))
+            if (context.allowBlur && (m_parsedCalculation ? m_parsedCalculation->isNegative() : !validUnit(val, FLength | FNonNeg, HTMLStandardMode)))
                 return nullptr;
 
             // A length is allowed here.  Construct the value and add it.