Changeset 287362 in webkit

Timestamp:

Dec 22, 2021 10:33:49 AM (7 months ago)

Author:

Antti Koivisto

Message:

[:has() pseudo-class] :has() selector does not render on first pass?
​https://bugs.webkit.org/show_bug.cgi?id=234531

Reviewed by Simon Fraser.

Source/WebCore:

With :has() identical sibling elements can have different style which breaks the current
assumptions of the style sharing optimization.

Test: fast/selectors/has-style-sharing.html

• style/StyleSharingResolver.cpp:

(WebCore::Style::SharingResolver::resolve):

Disable style sharing in presence of :has() rules for now.

For a less heavy-handed approach we need to start testing for :has() rules similar to what is already done
for sibling and attribute rules.

LayoutTests:

Test case by Alex Riviere.

• fast/selectors/has-style-sharing-expected.html: Added.
• fast/selectors/has-style-sharing.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/selectors/has-style-sharing-expected.html (added)
• LayoutTests/fast/selectors/has-style-sharing.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/style/StyleSharingResolver.cpp (modified) (1 diff)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2021-12-22  Antti Koivisto  <antti@apple.com>
+
+        [:has() pseudo-class] :has() selector does not render on first pass?
+        https://bugs.webkit.org/show_bug.cgi?id=234531
+
+        Reviewed by Simon Fraser.
+
+        Test case by Alex Riviere.
+
+        * fast/selectors/has-style-sharing-expected.html: Added.
+        * fast/selectors/has-style-sharing.html: Added.
+
 2021-12-22  Commit Queue  <commit-queue@webkit.org>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2021-12-22  Antti Koivisto  <antti@apple.com>
+
+        [:has() pseudo-class] :has() selector does not render on first pass?
+        https://bugs.webkit.org/show_bug.cgi?id=234531
+
+        Reviewed by Simon Fraser.
+
+        With :has() identical sibling elements can have different style which breaks the current
+        assumptions of the style sharing optimization.
+
+        Test: fast/selectors/has-style-sharing.html
+
+        * style/StyleSharingResolver.cpp:
+        (WebCore::Style::SharingResolver::resolve):
+
+        Disable style sharing in presence of :has() rules for now.
+
+        For a less heavy-handed approach we need to start testing for :has() rules similar to what is already done
+        for sibling and attribute rules.
+
 2021-12-22  Michael Saboff  <msaboff@apple.com>
 

trunk/Source/WebCore/style/StyleSharingResolver.cpp

@@ -108 +108 @@
             return nullptr;
     }
+    // FIXME: Do something smarter here, for example RuleSet based matching like with attribute/sibling selectors.
+    if (Scope::forNode(element).usesHasPseudoClass())
+        return nullptr;
 
     Context context {