Only match style from element's TreeScope for normal rules.

Source/core/css/resolver/StyleResolver.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 368 matching lines @@
     // Note that we may get invoked for some random elements in some wacky cases during style resolve.
     // Pause maintaining the stack in this case.
     if (m_selectorFilter.parentStackIsConsistent(&parent))
         m_selectorFilter.popParent();
 }
 
 StyleResolver::~StyleResolver()
 {
 }
 
-void StyleResolver::matchAuthorRulesForShadowHost(Element* element, ElementRuleCollector& collector, bool includeEmptyRules, WillBeHeapVector<RawPtrWillBeMember<ScopedStyleResolver>, 8>& resolvers, WillBeHeapVector<RawPtrWillBeMember<ScopedStyleResolver>, 8>& resolversInShadowTree)
+static inline ScopedStyleResolver* scopedResolverFor(const Element* element)
 {
-    collector.clearMatchedRules();
-    collector.matchedResult().ranges.lastAuthorRule = collector.matchedResult().matchedProperties.size() - 1;
+    // Ideally, returning element->treeScope().scopedStyleResolver() should be
+    // enough, but ::cue and custom pseudo elements like ::-webkit-meter-bar pierce
+    // through a shadow dom boundary, yet they are not part of m_treeBoundaryCrossingRules.
+    // The assumption here is that these rules only pierce through one boundary and
+    // that the scope of these elements do not have a style resolver due to the fact
+    // that VTT scopes and UA shadow trees don't have <style> elements. This is
+    // backed up by the ASSERTs below.
+    //
+    // FIXME: Make ::cue and custom pseudo elements part of boundary crossing rules
+    // when moving those rules to ScopedStyleResolver as part of issue 401359.
 
-    CascadeScope cascadeScope = 0;
+    TreeScope* treeScope = &element->treeScope();
+    if (ScopedStyleResolver* resolver = treeScope->scopedStyleResolver()) {
+        ASSERT(element->shadowPseudoId().isEmpty());
+        ASSERT(!element->isVTTElement());
+        return resolver;
+    }
+
+    treeScope = treeScope->parentTreeScope();
+    if (!treeScope)
+        return nullptr;
+    if (element->shadowPseudoId().isEmpty() && !element->isVTTElement())
+        return nullptr;
+    return treeScope->scopedStyleResolver();
+}
+
+void StyleResolver::matchAuthorRulesForShadowHost(Element* element, ElementRuleCollector& collector, bool includeEmptyRules, WillBeHeapVector<RawPtrWillBeMember<ScopedStyleResolver>, 8>& resolversInShadowTree)
+{
     CascadeOrder cascadeOrder = 0;
+    for (int j = resolversInShadowTree.size() - 1; j >= 0; --j)
+        resolversInShadowTree.at(j)->collectMatchingShadowHostRules(collector, includeEmptyRules, cascadeOrder++);
 
-    for (int j = resolversInShadowTree.size() - 1; j >= 0; --j)
-        resolversInShadowTree.at(j)->collectMatchingShadowHostRules(collector, includeEmptyRules, cascadeScope, cascadeOrder++);
-
-    if (resolvers.isEmpty() || resolvers.first()->treeScope() != element->treeScope())
-        ++cascadeScope;
-    cascadeOrder += resolvers.size();
-    for (unsigned i = 0; i < resolvers.size(); ++i)
-        resolvers.at(i)->collectMatchingAuthorRules(collector, includeEmptyRules, cascadeScope++, --cascadeOrder);
-
-    m_treeBoundaryCrossingRules.collectTreeBoundaryCrossingRules(element, collector, includeEmptyRules);
-    collector.sortAndTransferMatchedRules();
+    if (ScopedStyleResolver* resolver = scopedResolverFor(element))
+        resolver->collectMatchingAuthorRules(collector, includeEmptyRules, cascadeOrder);
 }
 
 void StyleResolver::matchAuthorRules(Element* element, ElementRuleCollector& collector, bool includeEmptyRules)
 {
     collector.clearMatchedRules();
     collector.matchedResult().ranges.lastAuthorRule = collector.matchedResult().matchedProperties.size() - 1;
 
     if (document().styleEngine()->onlyDocumentHasStyles()) {
         ScopedStyleResolver* resolver = document().scopedStyleResolver();
+        // If we have no resolver for a document, the document has no styles.
+        // We don't need to see any rules (including treeboundary crossing ones).
         if (!resolver)
             return;
-        // If we have no resolver for a document, the document has no styles.
-        // We don't need to see any rules (including treeboundary crossing ones).
-        resolver->collectMatchingAuthorRules(collector, includeEmptyRules, ignoreCascadeScope);
+        resolver->collectMatchingAuthorRules(collector, includeEmptyRules);
         m_treeBoundaryCrossingRules.collectTreeBoundaryCrossingRules(element, collector, includeEmptyRules);
         collector.sortAndTransferMatchedRules();
         return;
     }
 
-    WillBeHeapVector<RawPtrWillBeMember<ScopedStyleResolver>, 8> resolvers;
-    resolveScopedStyles(element, resolvers);
-
     WillBeHeapVector<RawPtrWillBeMember<ScopedStyleResolver>, 8> resolversInShadowTree;
     collectScopedResolversForHostedShadowTrees(element, resolversInShadowTree);
-    if (!resolversInShadowTree.isEmpty()) {
-        matchAuthorRulesForShadowHost(element, collector, includeEmptyRules, resolvers, resolversInShadowTree);
-        return;
-    }
-
-    if (!resolvers.isEmpty()) {
-        CascadeScope cascadeScope = 0;
-        CascadeOrder cascadeOrder = resolvers.size();
-        for (unsigned i = 0; i < resolvers.size(); ++i, --cascadeOrder) {
-            ScopedStyleResolver* resolver = resolvers.at(i);
-            // FIXME: Need to clarify how to treat style scoped.
-            resolver->collectMatchingAuthorRules(collector, includeEmptyRules, cascadeScope++, resolver->treeScope() == element->treeScope() && resolver->treeScope().rootNode().isShadowRoot() ? 0 : cascadeOrder);
-        }
-    }
+    if (!resolversInShadowTree.isEmpty())
+        matchAuthorRulesForShadowHost(element, collector, includeEmptyRules, resolversInShadowTree);
+    else if (ScopedStyleResolver* resolver = scopedResolverFor(element))
+        resolver->collectMatchingAuthorRules(collector, includeEmptyRules, resolver->treeScope().rootNode().isShadowRoot() ? 0 : 1);
 
     m_treeBoundaryCrossingRules.collectTreeBoundaryCrossingRules(element, collector, includeEmptyRules);
     collector.sortAndTransferMatchedRules();
 }
 
 void StyleResolver::matchUARules(ElementRuleCollector& collector)
 {
     collector.setMatchingUARules(true);
 
     CSSDefaultStyleSheets& defaultStyleSheets = CSSDefaultStyleSheets::instance();
@@ skipping 560 matching lines @@
     applyAnimatedProperties<LowPriorityProperties>(state, activeInterpolationsForTransitions);
 
     // Start loading resources used by animations.
     loadPendingResources(state);
 
     ASSERT(!state.fontBuilder().fontDirty());
 
     return true;
 }
 
-static inline ScopedStyleResolver* scopedResolverFor(const Element* element)
-{
-    for (TreeScope* treeScope = &element->treeScope(); treeScope; treeScope = treeScope->parentTreeScope()) {
-        if (ScopedStyleResolver* scopedStyleResolver = treeScope->scopedStyleResolver())
-            return scopedStyleResolver;
-    }
-    return 0;
-}
-
-void StyleResolver::resolveScopedStyles(const Element* element, WillBeHeapVector<RawPtrWillBeMember<ScopedStyleResolver>, 8>& resolvers)
-{
-    for (ScopedStyleResolver* scopedResolver = scopedResolverFor(element); scopedResolver; scopedResolver = scopedResolver->parent())
-        resolvers.append(scopedResolver);
-}
-
 const StyleRuleKeyframes* StyleResolver::findKeyframesRule(const Element* element, const AtomicString& animationName)
 {
     WillBeHeapVector<RawPtrWillBeMember<ScopedStyleResolver>, 8> resolvers;
     collectScopedResolversForHostedShadowTrees(element, resolvers);
     if (ScopedStyleResolver* scopedResolver = element->treeScope().scopedStyleResolver())
         resolvers.append(scopedResolver);
 
     for (size_t i = 0; i < resolvers.size(); ++i) {
         if (const StyleRuleKeyframes* keyframesRule = resolvers[i]->keyframeStylesForAnimation(animationName.impl()))
             return keyframesRule;
@@ skipping 553 matching lines @@
     visitor->trace(m_uncommonAttributeRuleSet);
     visitor->trace(m_watchedSelectorsRules);
     visitor->trace(m_treeBoundaryCrossingRules);
     visitor->trace(m_styleSharingLists);
     visitor->trace(m_pendingStyleSheets);
     visitor->trace(m_document);
 #endif
 }
 
 } // namespace blink