Default @namespace should not apply to VTT type selectors

Ignore default namespace when parsing ::cue() parameter as a type
selector.

Bug: 1166850
Change-Id: I4fde0fe1f36e15dbd8390ea0ace218739ed1ec7b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2631485Reviewed-by: Anders Hartvoll Ruud <andruud@chromium.org>
Reviewed-by: Fredrik Söderquist <fs@opera.com>
Commit-Queue: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844065}

third_party/blink/renderer/core/css/css_selector_test.cc

@@ -165,4 +165,25 @@ TEST(CSSSelector, HasLinkOrVisited) {
   EXPECT_TRUE(HasLinkOrVisited(":host-context(:link)"));
 }
 
+TEST(CSSSelector, CueDefaultNamespace) {
+  css_test_helpers::TestStyleSheet sheet;
+
+  sheet.AddCSSRules(R"HTML(
+    @namespace "http://www.w3.org/1999/xhtml";
+    video::cue(b) {}
+  )HTML");
+
+  const CSSSelector& cue_selector =
+      (*sheet.GetRuleSet().CuePseudoRules())[0]->Selector();
+  EXPECT_EQ(cue_selector.GetPseudoType(), CSSSelector::kPseudoCue);
+
+  const CSSSelectorList* cue_arguments = cue_selector.SelectorList();
+  ASSERT_TRUE(cue_arguments);
+  const CSSSelector* vtt_type_selector = cue_arguments->First();
+  ASSERT_TRUE(vtt_type_selector);
+  EXPECT_EQ(vtt_type_selector->TagQName().LocalName(), "b");
+  // Default namespace should not affect VTT node type selector.
+  EXPECT_EQ(vtt_type_selector->TagQName().NamespaceURI(), g_star_atom);
+}
+
 }  // namespace blink

third_party/blink/renderer/core/css/parser/css_selector_parser.cc

@@ -34,7 +34,7 @@ CSSParserTokenRange ConsumeNestedArgument(CSSParserTokenRange& range) {
   return range.MakeSubRange(&first, &range.Peek());
 }
 
-bool AtEndIgnoringWhitepace(CSSParserTokenRange range) {
+bool AtEndIgnoringWhitespace(CSSParserTokenRange range) {
   range.ConsumeWhitespace();
   return range.AtEnd();
 }
@@ -427,8 +427,9 @@ std::unique_ptr<CSSParserSelector> CSSSelectorParser::ConsumeCompoundSelector(
   // [1] https://drafts.csswg.org/selectors/#matches
   // [2] https://drafts.csswg.org/selectors/#selector-subject
   base::AutoReset<bool> ignore_namespace(
-      &ignore_default_namespace_, resist_default_namespace_ && !has_q_name &&
-                                      AtEndIgnoringWhitepace(range));
+      &ignore_default_namespace_,
+      ignore_default_namespace_ || (resist_default_namespace_ && !has_q_name &&
+                                    AtEndIgnoringWhitespace(range)));
 
   if (!compound_selector) {
     AtomicString namespace_uri = DetermineNamespace(namespace_prefix);
@@ -699,6 +700,10 @@ std::unique_ptr<CSSParserSelector> CSSSelectorParser::ConsumePseudo(
     case CSSSelector::kPseudoCue: {
       DisallowPseudoElementsScope scope(this);
       base::AutoReset<bool> inside_compound(&inside_compound_pseudo_, true);
+      base::AutoReset<bool> ignore_namespace(
+          &ignore_default_namespace_,
+          ignore_default_namespace_ ||
+              selector->GetPseudoType() == CSSSelector::kPseudoCue);
 
       std::unique_ptr<CSSSelectorList> selector_list =
           std::make_unique<CSSSelectorList>();