SelectorChecker::parentElement should walk up to ShadowHost only if an element is in a shadow tree …

Source/core/css/SelectorChecker.cpp

Index: Source/core/css/SelectorChecker.cpp
diff --git a/Source/core/css/SelectorChecker.cpp b/Source/core/css/SelectorChecker.cpp
index eff32607837754fcff7e2bca5a3902e7eff25b5e..cc023da531c544ca9e7c6c5304e925a22c7c647a 100644
--- a/Source/core/css/SelectorChecker.cpp
+++ b/Source/core/css/SelectorChecker.cpp
@@ -84,7 +84,7 @@ Element* SelectorChecker::parentElement(const SelectorCheckingContext& context,
         return context.element->parentOrShadowHostElement();
 
     // If context.scope is a shadow host, we should walk up from a shadow root to its shadow host.
-    if (context.behaviorAtBoundary & SelectorChecker::ScopeIsShadowHost)
+    if ((context.behaviorAtBoundary & SelectorChecker::ScopeIsShadowHost) && context.scope == context.element->shadowHost())
         return context.element->parentOrShadowHostElement();
 
     if ((context.behaviorAtBoundary & SelectorChecker::BoundaryBehaviorMask) != SelectorChecker::StaysWithinTreeScope)