Changeset 285262 in webkit

Timestamp:

Nov 4, 2021 9:15:14 AM (9 months ago)

Author:

Antti Koivisto

Message:

:host::part(foo) selector does not select elements inside shadow roots
​https://bugs.webkit.org/show_bug.cgi?id=232261
<rdar://problem/84894922>

Reviewed by Simon Fraser.

We need to also look for ::part rules from the element's own scope.

• css/SelectorChecker.cpp:

(WebCore::SelectorChecker::match const):

Rename mayMatchHostPseudoClass -> mustMatchHostPseudoClass for clarity.

(WebCore::localContextForParent):
(WebCore::SelectorChecker::matchRecursively const):

Split ShadowDescendant and ShadowPartDescendant handling as they are sufficiently different.
Set nextContext.mustMatchHostPseudoClass bit for ::part rules coming from the Element's scope as
it is the only way they can match.

(WebCore::SelectorChecker::checkOne const):

No name mapping for rules from the element's own scope.

• style/ElementRuleCollector.cpp:

(WebCore::Style::ElementRuleCollector::matchPartPseudoElementRules):
(WebCore::Style::ElementRuleCollector::matchPartPseudoElementRulesForScope):

Also check ::part rules from the element scope.

• style/ElementRuleCollector.h:

Location:

trunk

Files:

• LayoutTests/imported/w3c/web-platform-tests/css/css-shadow-parts/host-part-001-expected.txt (modified) (1 diff)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/css/SelectorChecker.cpp (modified) (9 diffs)
• Source/WebCore/style/ElementRuleCollector.cpp (modified) (2 diffs)
• Source/WebCore/style/ElementRuleCollector.h (modified) (1 diff)

trunk/LayoutTests/imported/w3c/web-platform-tests/css/css-shadow-parts/host-part-001-expected.txt

@@ -1 +1 @@
 
-FAIL :host::part works assert_equals: :host::part() works expected "rgb(0, 255, 0)" but got "rgb(0, 0, 0)"
+PASS :host::part works
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2021-11-04  Antti Koivisto  <antti@apple.com>
+
+        :host::part(foo) selector does not select elements inside shadow roots
+        https://bugs.webkit.org/show_bug.cgi?id=232261
+        <rdar://problem/84894922>
+
+        Reviewed by Simon Fraser.
+
+        We need to also look for ::part rules from the element's own scope.
+
+        * css/SelectorChecker.cpp:
+        (WebCore::SelectorChecker::match const):
+
+        Rename mayMatchHostPseudoClass -> mustMatchHostPseudoClass for clarity.
+
+        (WebCore::localContextForParent):
+        (WebCore::SelectorChecker::matchRecursively const):
+
+        Split ShadowDescendant and ShadowPartDescendant handling as they are sufficiently different.
+        Set nextContext.mustMatchHostPseudoClass bit for ::part rules coming from the Element's scope as
+        it is the only way they can match.
+
+        (WebCore::SelectorChecker::checkOne const):
+
+        No name mapping for rules from the element's own scope.
+
+        * style/ElementRuleCollector.cpp:
+        (WebCore::Style::ElementRuleCollector::matchPartPseudoElementRules):
+        (WebCore::Style::ElementRuleCollector::matchPartPseudoElementRulesForScope):
+
+        Also check ::part rules from the element scope.
+
+        * style/ElementRuleCollector.h:
+
 2021-11-04  Andres Gonzalez  <andresg_22@apple.com>
 

trunk/Source/WebCore/css/SelectorChecker.cpp

@@ -77 +77 @@
     bool hasScrollbarPseudo { false };
     bool hasSelectionPseudo { false };
-    bool mayMatchHostPseudoClass { false };
+    bool mustMatchHostPseudoClass { false };
 };
 
@@ -178 +178 @@
     if (checkingContext.isMatchingHostPseudoClass) {
         ASSERT(element.shadowRoot());
-        context.mayMatchHostPseudoClass = true;
+        context.mustMatchHostPseudoClass = true;
     }
 
@@ -237 +237 @@
     updatedContext.isSubjectOrAdjacentElement = false;
 
-    if (updatedContext.mayMatchHostPseudoClass) {
+    if (updatedContext.mustMatchHostPseudoClass) {
         updatedContext.element = nullptr;
         return updatedContext;
@@ -245 +245 @@
     if (context.selector->match() == CSSSelector::PseudoClass && context.selector->pseudoClassType() == CSSSelector::PseudoClassHost && is<ShadowRoot>(context.element->parentNode())) {
         updatedContext.element = downcast<ShadowRoot>(*context.element->parentNode()).host();
-        updatedContext.mayMatchHostPseudoClass = true;
+        updatedContext.mustMatchHostPseudoClass = true;
         return updatedContext;
     }
@@ -407 +407 @@
             return MatchResult::updateWithMatchType(result, matchType);
         }
-    case CSSSelector::ShadowDescendant:
-    case CSSSelector::ShadowPartDescendant: {
-        // Continue matching in the scope where this rule came from.
-        auto* host = relation == CSSSelector::ShadowPartDescendant
-            ? Style::hostForScopeOrdinal(*context.element, checkingContext.styleScopeOrdinal)
-            : context.element->shadowHost();
+    case CSSSelector::ShadowDescendant:  {
+        auto* host = context.element->shadowHost();
         if (!host)
             return MatchResult::fails(Match::SelectorFailsCompletely);
@@ -419 +415 @@
         nextContext.firstSelectorOfTheFragment = nextContext.selector;
         nextContext.isSubjectOrAdjacentElement = false;
+        PseudoIdSet ignoreDynamicPseudo;
+        MatchResult result = matchRecursively(checkingContext, nextContext, ignoreDynamicPseudo);
+
+        return MatchResult::updateWithMatchType(result, matchType);
+    }
+    case CSSSelector::ShadowPartDescendant: {
+        // Continue matching in the scope where this rule came from.
+        auto* host = checkingContext.styleScopeOrdinal == Style::ScopeOrdinal::Element
+            ? context.element->shadowHost()
+            : Style::hostForScopeOrdinal(*context.element, checkingContext.styleScopeOrdinal);
+        if (!host)
+            return MatchResult::fails(Match::SelectorFailsCompletely);
+
+        nextContext.element = host;
+        nextContext.firstSelectorOfTheFragment = nextContext.selector;
+        nextContext.isSubjectOrAdjacentElement = false;
+        // ::part rules from the element's own scope can only match if they apply to :host.
+        nextContext.mustMatchHostPseudoClass = checkingContext.styleScopeOrdinal == Style::ScopeOrdinal::Element;
         PseudoIdSet ignoreDynamicPseudo;
         MatchResult result = matchRecursively(checkingContext, nextContext, ignoreDynamicPseudo);
@@ -642 +656 @@
     const CSSSelector& selector = *context.selector;
 
-    if (context.mayMatchHostPseudoClass) {
+    if (context.mustMatchHostPseudoClass) {
         // :host doesn't combine with anything except pseudo elements.
         bool isHostPseudoClass = selector.match() == CSSSelector::PseudoClass && selector.pseudoClassType() == CSSSelector::PseudoClassHost;
@@ -1090 +1104 @@
         }
         case CSSSelector::PseudoClassHost: {
-            if (!context.mayMatchHostPseudoClass)
+            if (!context.mustMatchHostPseudoClass)
                 return false;
             return matchHostPseudoClass(selector, element, checkingContext);
@@ -1172 +1186 @@
             auto translatePartNameToRuleScope = [&](AtomString partName) {
                 Vector<AtomString, 1> mappedNames { partName };
+
+                if (checkingContext.styleScopeOrdinal == Style::ScopeOrdinal::Element)
+                    return mappedNames;
+
                 auto* ruleScopeHost = Style::hostForScopeOrdinal(*context.element, checkingContext.styleScopeOrdinal);
 

trunk/Source/WebCore/style/ElementRuleCollector.cpp

@@ -302 +302 @@
         return;
 
-    matchPartPseudoElementRulesForScope(*partMatchingElement.containingShadowRoot());
-}
-
-void ElementRuleCollector::matchPartPseudoElementRulesForScope(const ShadowRoot& scopeShadowRoot)
-{
-    auto* host = scopeShadowRoot.host();
-    auto styleScopeOrdinal = ScopeOrdinal::ContainingHost;
-
-    for (; host; host = host->shadowHost(), --styleScopeOrdinal) {
-        auto& styleScope = Scope::forNode(*host);
+    matchPartPseudoElementRulesForScope(partMatchingElement);
+}
+
+void ElementRuleCollector::matchPartPseudoElementRulesForScope(const Element& partMatchingElement)
+{
+    auto* element = &partMatchingElement;
+    auto styleScopeOrdinal = ScopeOrdinal::Element;
+
+    for (; element; element = element->shadowHost(), --styleScopeOrdinal) {
+        auto& styleScope = Scope::forNode(const_cast<Element&>(*element));
         if (!styleScope.resolver().ruleSets().isAuthorStyleDefined())
             continue;
@@ -321 +321 @@
 
         // Element may only be exposed to styling from enclosing scopes via exportparts attributes.
-        if (host->shadowRoot()->partMappings().isEmpty())
+        if (element != &partMatchingElement && element->shadowRoot()->partMappings().isEmpty())
             break;
     }

trunk/Source/WebCore/style/ElementRuleCollector.h

@@ -133 +133 @@
     void matchSlottedPseudoElementRules();
     void matchPartPseudoElementRules();
-    void matchPartPseudoElementRulesForScope(const ShadowRoot& scopeShadowRoot);
+    void matchPartPseudoElementRulesForScope(const Element& partMatchingElement);
 
     void collectMatchingShadowPseudoElementRules(const MatchRequest&);