[css-nesting] Keep parsing after {}-block for rules with invalid sele…

…ctor When encountering a rule with an invalid selector, we currently recover by consuming until the next semicolon, which isn't correct. Instead, we should simply do nothing, and keep parsing right after the {}-block. The spec used to be less clear about this, but at least at the time of writing, nothing invokes the skip-until-semicolon behavior except for rule preludes that look like custom properties. This CL fixes this issue by adding a `invalid_rule_error` out-param to ConsumeStyleRule. There are two other things that are worth noting: - The "consume a qualified rule" algorithm in the spec mentions a `nested` flag which modifies its behavior. This flag is actually equivalent to `semicolon_aborts_nested_selector` in our parser, so I've renamed this. - During handling of `custom_property_ambiguity`, nested=false case, we're supposed to consume a block, and do nothing. This can't be tested using CSSParserImpl's public API, since failing to consume a block there would just cause the next attempt at parsing a rule to consume an empty prelude (then the block). But I don't think we should rely on that, hence I'm using unit tests to cover that line. [1] https://drafts.csswg.org/css-syntax/#consume-qualified-rule Test: external/wpt/css/css-syntax/custom-property-rule-ambiguity.html Change-Id: I04dc0c3745be5eafe792fd6c40971545274d9794 Fixed: 343979378 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5881815 Commit-Queue: Anders Hartvoll Ruud <andruud@chromium.org> Reviewed-by: Steinar H Gunderson <sesse@chromium.org> Cr-Commit-Position: refs/heads/main@{#1359288}
web-platform-tests · Sep 24, 2024 · 8ae822f · 8ae822f
1 parent 266b949
commit 8ae822f
Showing 1 changed file with 21 additions and 0 deletions.
diff --git a/css/css-syntax/invalid-nested-rules.html b/css/css-syntax/invalid-nested-rules.html
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+<!DOCTYPE html>
+<title>CSS Syntax: invalid rule errors when nested</title>
+<link rel="help" href="https://drafts.csswg.org/css-syntax/#invalid-rule-error">
+<link rel="help" href="https://drafts.csswg.org/css-syntax/#consume-qualified-rule">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<style id=style>
+  .a {
+    .b <::::invalid::::> {}
+    & .c {}
+  }
+</style>
+<script>
+  test(() => {
+    let rules = style.sheet.rules;
+    assert_equals(rules.length, 1);
+    let childRules = rules[0].cssRules;
+    assert_equals(childRules.length, 1);
+    assert_equals(childRules[0].selectorText, '& .c');
+  }, 'Continues parsing after block on invalid rule error');
+</script>