Skip child ShadowRoots when invalidation does not have boundary crossing rules

Source/core/css/RuleFeature.cpp

Index: Source/core/css/RuleFeature.cpp
diff --git a/Source/core/css/RuleFeature.cpp b/Source/core/css/RuleFeature.cpp
index 6adb2dc6fcfdb6c2da48c0f0d9dc3528d7449be8..398617cce869c69683dc59e9130fb3a7568afb5a 100644
--- a/Source/core/css/RuleFeature.cpp
+++ b/Source/core/css/RuleFeature.cpp
@@ -207,13 +207,8 @@ RuleFeatureSet::InvalidationSetMode RuleFeatureSet::updateInvalidationSets(const
         return mode;
 
     InvalidationSetFeatures features;
-    const CSSSelector* current = extractInvalidationSetFeatures(selector, features);
-    if (current) {
-        bool wholeSubtree = current->relation() == CSSSelector::DirectAdjacent || current->relation() == CSSSelector::IndirectAdjacent;
-        current = current->tagHistory();
-        if (current)
-            addFeaturesToInvalidationSets(*current, features, wholeSubtree);
-    }
+    if (const CSSSelector* current = extractInvalidationSetFeatures(selector, features))
+        addFeaturesToInvalidationSets(*current, features);
     return AddFeatures;
 }
 
@@ -231,17 +226,26 @@ const CSSSelector* RuleFeatureSet::extractInvalidationSetFeatures(const CSSSelec
             }
         }
 
+        if (lastSelector->relation() == CSSSelector::ShadowPseudo || lastSelector->relation() == CSSSelector::ShadowDeep)
+            features.treeBoundaryCrossing = true;
+        else if (lastSelector->relation() == CSSSelector::DirectAdjacent || lastSelector->relation() == CSSSelector::IndirectAdjacent)
+            features.wholeSubtree = true;
+
         if (lastSelector->relation() != CSSSelector::SubSelector)
             break;
     }
-    return lastSelector;
+    if (lastSelector)
+        return lastSelector->tagHistory();
+    return 0;
 }
 
-void RuleFeatureSet::addFeaturesToInvalidationSets(const CSSSelector& selector, const InvalidationSetFeatures& features, bool wholeSubtree)
+void RuleFeatureSet::addFeaturesToInvalidationSets(const CSSSelector& selector, InvalidationSetFeatures& features)
 {
     for (const CSSSelector* current = &selector; current; current = current->tagHistory()) {
         if (DescendantInvalidationSet* invalidationSet = invalidationSetForSelector(*current)) {
-            if (wholeSubtree) {
+            if (features.treeBoundaryCrossing)
+                invalidationSet->setTreeBoundaryCrossing();
+            if (features.wholeSubtree) {
                 invalidationSet->setWholeSubtreeInvalid();
             } else {
                 if (!features.id.isEmpty())
@@ -256,28 +260,29 @@ void RuleFeatureSet::addFeaturesToInvalidationSets(const CSSSelector& selector,
                     invalidationSet->setCustomPseudoInvalid();
             }
         } else if (current->pseudoType() == CSSSelector::PseudoHost || current->pseudoType() == CSSSelector::PseudoAny) {
+            if (current->pseudoType() == CSSSelector::PseudoHost)
+                features.treeBoundaryCrossing = true;
             if (const CSSSelectorList* selectorList = current->selectorList()) {
                 for (const CSSSelector* selector = selectorList->first(); selector; selector = CSSSelectorList::next(*selector))
-                    addFeaturesToInvalidationSets(*selector, features, wholeSubtree);
+                    addFeaturesToInvalidationSets(*selector, features);
             }
         }
         switch (current->relation()) {
         case CSSSelector::Descendant:
         case CSSSelector::Child:
+            features.wholeSubtree = false;

[chrishtr, 2014/05/29 20:54:07]

Why this change?

[esprehn, 2014/05/29 21:07:30]

Because I can't handle all 4 types of relations the same way anymore.

[chrishtr, 2014/05/29 21:43:43]

Ah right, fallthrough.

+            break;
         case CSSSelector::ShadowPseudo:
         case CSSSelector::ShadowDeep:
-            wholeSubtree = false;
+            features.treeBoundaryCrossing = true;
+            features.wholeSubtree = false;

[chrishtr, 2014/05/29 20:54:07]

I don't get why it's ok to set wholeSubtree to false here.

[esprehn, 2014/05/29 21:07:30]

We always did that, see the old code. I just split the two cases apart so that
ShadowPseudo/ShadowDeep set both wholeSubtree and treeBoundaryCrossing, and
DirectAdjacent/IndirectAdjacent only set wholeSubtree.

[chrishtr, 2014/05/29 21:43:43]

Oh right.

[chrishtr, 2014/05/29 21:43:43]

Ok.

[rune, 2014/05/30 21:02:45]

FTR, it's because these shadow combinators are like descendant combinators, and
wholeSubtree in this context is about adjacent combinators requiring
wholeSubtree because the features of the rightmost compound selector are not of
a descendant. That is however canceled out as encountering a descendant-like
combinator will make the rightmost compound selector start matching a descendant
again.

.a /deep/ .b + .c // .c not a descendant of .b, but .c a descendant of .a

             break;
         case CSSSelector::DirectAdjacent:
         case CSSSelector::IndirectAdjacent:
-            wholeSubtree = true;
+            features.wholeSubtree = true;
             break;
         case CSSSelector::SubSelector:
             break;
-        default:
-            // All combinators should be handled above.
-            ASSERT_NOT_REACHED();
-            break;
         }
     }
 }