Auto merge of #16890 - servo:qname, r=emilio

Fix serialization of namespace and universal selectors

Fix #16017
Fix #16020

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5 files changed, 313 insertions, 88 deletions

diff --git a/components/selectors/matching.rs b/components/selectors/matching.rs
index ebc31fa7b53..c4e19f47fd3 100644
--- a/components/selectors/matching.rs
+++ b/components/selectors/matching.rs
@@ -3,7 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 use bloom::BloomFilter;
 use parser::{CaseSensitivity, Combinator, ComplexSelector, Component, LocalName};
-use parser::{Selector, SelectorInner, SelectorIter};
+use parser::{Selector, SelectorInner, SelectorIter, SelectorImpl};
 use std::borrow::Borrow;
 use tree::Element;
 
@@ -310,8 +310,18 @@ fn matches_simple_selector<E, F>(
             let name = if element.is_html_element_in_html_document() { lower_name } else { name };
             element.get_local_name() == name.borrow()
         }
-        Component::Namespace(ref namespace) => {
-            element.get_namespace() == namespace.url.borrow()
+        Component::ExplicitUniversalType |
+        Component::ExplicitAnyNamespace => {
+            true
+        }
+        Component::Namespace(_, ref url) |
+        Component::DefaultNamespace(ref url) => {
+            element.get_namespace() == url.borrow()
+        }
+        Component::ExplicitNoNamespace => {
+            // Rust type’s default, not default namespace
+            let empty_string = <E::Impl as SelectorImpl>::NamespaceUrl::default();
+            element.get_namespace() == empty_string.borrow()
         }
         // TODO: case-sensitivity depends on the document type and quirks mode
         Component::ID(ref id) => {
diff --git a/components/selectors/parser.rs b/components/selectors/parser.rs
index 82571d9bd5e..34ed4418b3d 100644
--- a/components/selectors/parser.rs
+++ b/components/selectors/parser.rs
@@ -182,6 +182,18 @@ pub struct Selector<Impl: SelectorImpl> {
     pub specificity: u32,
 }
 
+impl<Impl: SelectorImpl> Selector<Impl> {
+    /// Whether this selector (pseudo-element part excluded) matches every element.
+    ///
+    /// Used for "pre-computed" pseudo-elements in components/style/stylist.rs
+    pub fn is_universal(&self) -> bool {
+        self.inner.complex.iter_raw().all(|c| matches!(*c,
+            Component::ExplicitUniversalType |
+            Component::ExplicitAnyNamespace
+        ))
+    }
+}
+
 pub trait SelectorMethods {
     type Impl: SelectorImpl;
 
@@ -431,10 +443,17 @@ impl Combinator {
 #[derive(Eq, PartialEq, Clone)]
 pub enum Component<Impl: SelectorImpl> {
     Combinator(Combinator),
+
+    ExplicitAnyNamespace,
+    ExplicitNoNamespace,
+    DefaultNamespace(Impl::NamespaceUrl),
+    Namespace(Impl::NamespacePrefix, Impl::NamespaceUrl),
+
+    ExplicitUniversalType,
+    LocalName(LocalName<Impl>),
+
     ID(Impl::Identifier),
     Class(Impl::ClassName),
-    LocalName(LocalName<Impl>),
-    Namespace(Namespace<Impl>),
 
     // Attribute selectors
     AttrExists(AttrSelector<Impl>),  // [foo]
@@ -489,8 +508,9 @@ impl<Impl: SelectorImpl> Component<Impl> {
                     None
                 }
             },
-            Component::Namespace(ref namespace) => {
-                Some(namespace.url.precomputed_hash())
+            Component::DefaultNamespace(ref url) |
+            Component::Namespace(_, ref url) => {
+                Some(url.precomputed_hash())
             },
             Component::ID(ref id) => {
                 Some(id.precomputed_hash())
@@ -646,7 +666,15 @@ impl<Impl: SelectorImpl> ToCss for Component<Impl> {
                 display_to_css_identifier(s, dest)
             }
             LocalName(ref s) => s.to_css(dest),
-            Namespace(ref ns) => ns.to_css(dest),
+            ExplicitUniversalType => dest.write_char('*'),
+
+            DefaultNamespace(_) => Ok(()),
+            ExplicitNoNamespace => dest.write_char('|'),
+            ExplicitAnyNamespace => dest.write_str("*|"),
+            Namespace(ref prefix, _) => {
+                display_to_css_identifier(prefix, dest)?;
+                dest.write_char('|')
+            }
 
             // Attribute selectors
             AttrExists(ref a) => {
@@ -673,7 +701,7 @@ impl<Impl: SelectorImpl> ToCss for Component<Impl> {
             // Pseudo-classes
             Negation(ref arg) => {
                 dest.write_str(":not(")?;
-                debug_assert!(arg.len() <= 1 || (arg.len() == 2 && matches!(arg[0], Component::Namespace(_))));
+                debug_assert!(single_simple_selector(arg));
                 for component in arg.iter() {
                     component.to_css(dest)?;
                 }
@@ -832,10 +860,12 @@ fn complex_selector_specificity<Impl>(selector: &ComplexSelector<Impl>)
                                          where Impl: SelectorImpl {
         match *simple_selector {
             Component::Combinator(..) => unreachable!(),
-            Component::LocalName(..) =>
-                specificity.element_selectors += 1,
-            Component::ID(..) =>
-                specificity.id_selectors += 1,
+            Component::LocalName(..) => {
+                specificity.element_selectors += 1
+            }
+            Component::ID(..) => {
+                specificity.id_selectors += 1
+            }
             Component::Class(..) |
             Component::AttrExists(..) |
             Component::AttrEqual(..) |
@@ -859,10 +889,16 @@ fn complex_selector_specificity<Impl>(selector: &ComplexSelector<Impl>)
             Component::NthLastOfType(..) |
             Component::FirstOfType | Component::LastOfType |
             Component::OnlyOfType |
-            Component::NonTSPseudoClass(..) =>
-                specificity.class_like_selectors += 1,
-
-            Component::Namespace(..) => (),
+            Component::NonTSPseudoClass(..) => {
+                specificity.class_like_selectors += 1
+            }
+            Component::ExplicitUniversalType |
+            Component::ExplicitAnyNamespace |
+            Component::ExplicitNoNamespace |
+            Component::DefaultNamespace(..) |
+            Component::Namespace(..) => {
+                // Does not affect specificity
+            }
             Component::Negation(ref negated) => {
                 for ss in negated.iter() {
                     simple_selector_specificity(&ss, specificity);
@@ -990,10 +1026,22 @@ fn parse_type_selector<P, Impl>(parser: &P, input: &mut CssParser, sequence: &mu
         None => Ok(false),
         Some((namespace, local_name)) => {
             match namespace {
-                NamespaceConstraint::Specific(ns) => {
-                    sequence.push(Component::Namespace(ns))
-                },
-                NamespaceConstraint::Any => (),
+                QNamePrefix::ImplicitAnyNamespace => {}
+                QNamePrefix::ImplicitDefaultNamespace(url) => {
+                    sequence.push(Component::DefaultNamespace(url))
+                }
+                QNamePrefix::ExplicitNamespace(prefix, url) => {
+                    sequence.push(Component::Namespace(prefix, url))
+                }
+                QNamePrefix::ExplicitNoNamespace => {
+                    sequence.push(Component::ExplicitNoNamespace)
+                }
+                QNamePrefix::ExplicitAnyNamespace => {
+                    sequence.push(Component::ExplicitAnyNamespace)
+                }
+                QNamePrefix::ImplicitNoNamespace => {
+                    unreachable!()  // Not returned with in_attr_selector = false
+                }
             }
             match local_name {
                 Some(name) => {
@@ -1002,7 +1050,9 @@ fn parse_type_selector<P, Impl>(parser: &P, input: &mut CssParser, sequence: &mu
                         name: from_cow_str(name),
                     }))
                 }
-                None => (),
+                None => {
+                    sequence.push(Component::ExplicitUniversalType)
+                }
             }
             Ok(true)
         }
@@ -1015,22 +1065,29 @@ enum SimpleSelectorParseResult<Impl: SelectorImpl> {
     PseudoElement(Impl::PseudoElementSelector),
 }
 
+#[derive(Debug)]
+enum QNamePrefix<Impl: SelectorImpl> {
+    ImplicitNoNamespace, // `foo` in attr selectors
+    ImplicitAnyNamespace, // `foo` in type selectors, without a default ns
+    ImplicitDefaultNamespace(Impl::NamespaceUrl),  // `foo` in type selectors, with a default ns
+    ExplicitNoNamespace,  // `|foo`
+    ExplicitAnyNamespace,  // `*|foo`
+    ExplicitNamespace(Impl::NamespacePrefix, Impl::NamespaceUrl),  // `prefix|foo`
+}
+
 /// * `Err(())`: Invalid selector, abort
 /// * `Ok(None)`: Not a simple selector, could be something else. `input` was not consumed.
 /// * `Ok(Some((namespace, local_name)))`: `None` for the local name means a `*` universal selector
 fn parse_qualified_name<'i, 't, P, Impl>
                        (parser: &P, input: &mut CssParser<'i, 't>,
                         in_attr_selector: bool)
-                        -> Result<Option<(NamespaceConstraint<Impl>, Option<Cow<'i, str>>)>, ()>
+                        -> Result<Option<(QNamePrefix<Impl>, Option<Cow<'i, str>>)>, ()>
     where P: Parser<Impl=Impl>, Impl: SelectorImpl
 {
     let default_namespace = |local_name| {
         let namespace = match parser.default_namespace() {
-            Some(url) => NamespaceConstraint::Specific(Namespace {
-                prefix: None,
-                url: url
-            }),
-            None => NamespaceConstraint::Any,
+            Some(url) => QNamePrefix::ImplicitDefaultNamespace(url),
+            None => QNamePrefix::ImplicitAnyNamespace,
         };
         Ok(Some((namespace, local_name)))
     };
@@ -1056,15 +1113,12 @@ fn parse_qualified_name<'i, 't, P, Impl>
                     let prefix = from_cow_str(value);
                     let result = parser.namespace_for_prefix(&prefix);
                     let url = result.ok_or(())?;
-                    explicit_namespace(input, NamespaceConstraint::Specific(Namespace {
-                        prefix: Some(prefix),
-                        url: url
-                    }))
+                    explicit_namespace(input, QNamePrefix::ExplicitNamespace(prefix, url))
                 },
                 _ => {
                     input.reset(position);
                     if in_attr_selector {
-                        Ok(Some((NamespaceConstraint::Specific(Default::default()), Some(value))))
+                        Ok(Some((QNamePrefix::ImplicitNoNamespace, Some(value))))
                     } else {
                         default_namespace(Some(value))
                     }
@@ -1074,7 +1128,9 @@ fn parse_qualified_name<'i, 't, P, Impl>
         Ok(Token::Delim('*')) => {
             let position = input.position();
             match input.next_including_whitespace() {
-                Ok(Token::Delim('|')) => explicit_namespace(input, NamespaceConstraint::Any),
+                Ok(Token::Delim('|')) => {
+                    explicit_namespace(input, QNamePrefix::ExplicitAnyNamespace)
+                }
                 _ => {
                     input.reset(position);
                     if in_attr_selector {
@@ -1086,7 +1142,7 @@ fn parse_qualified_name<'i, 't, P, Impl>
             }
         },
         Ok(Token::Delim('|')) => {
-            explicit_namespace(input, NamespaceConstraint::Specific(Default::default()))
+            explicit_namespace(input, QNamePrefix::ExplicitNoNamespace)
         }
         _ => {
             input.reset(position);
@@ -1104,7 +1160,28 @@ fn parse_attribute_selector<P, Impl>(parser: &P, input: &mut CssParser)
         None => return Err(()),
         Some((_, None)) => unreachable!(),
         Some((namespace, Some(local_name))) => AttrSelector {
-            namespace: namespace,
+            namespace: match namespace {
+                QNamePrefix::ImplicitNoNamespace |
+                QNamePrefix::ExplicitNoNamespace => {
+                    NamespaceConstraint::Specific(Namespace {
+                        prefix: None,
+                        url: Impl::NamespaceUrl::default(),
+                    })
+                }
+                QNamePrefix::ExplicitNamespace(prefix, url) => {
+                    NamespaceConstraint::Specific(Namespace {
+                        prefix: Some(prefix),
+                        url: url,
+                    })
+                }
+                QNamePrefix::ExplicitAnyNamespace => {
+                    NamespaceConstraint::Any
+                }
+                QNamePrefix::ImplicitAnyNamespace |
+                QNamePrefix::ImplicitDefaultNamespace(_) => {
+                    unreachable!()  // Not returned with in_attr_selector = true
+                }
+            },
             lower_name: from_ascii_lowercase(&local_name),
             name: from_cow_str(local_name),
         },
@@ -1187,17 +1264,33 @@ fn parse_negation<P, Impl>(parser: &P,
     let mut v = ParseVec::new();
     parse_compound_selector(parser, input, &mut v, /* inside_negation = */ true)?;
 
-    let allow = v.len() <= 1 ||
-        (v.len() == 2 && matches!(v[0], Component::Namespace(_)) &&
-         matches!(v[1], Component::LocalName(_)));
-
-    if allow {
+    if single_simple_selector(&v) {
         Ok(Component::Negation(v.into_vec().into_boxed_slice()))
     } else {
         Err(())
     }
 }
 
+// A single type selector can be represented as two components
+fn single_simple_selector<Impl: SelectorImpl>(v: &[Component<Impl>]) -> bool {
+    v.len() == 1 || (
+        v.len() == 2 &&
+        match v[1] {
+            Component::LocalName(_) | Component::ExplicitUniversalType => {
+                debug_assert!(matches!(v[0],
+                    Component::ExplicitAnyNamespace |
+                    Component::ExplicitNoNamespace |
+                    Component::DefaultNamespace(_) |
+                    Component::Namespace(..)
+                ));
+                true
+            }
+            _ => false,
+        }
+    )
+
+}
+
 /// simple_selector_sequence
 /// : [ type_selector | universal ] [ HASH | class | attrib | pseudo | negation ]*
 /// | [ HASH | class | attrib | pseudo | negation ]+
@@ -1228,10 +1321,7 @@ fn parse_compound_selector<P, Impl>(
             //
             // Note that this doesn't apply to :not() and :matches() per spec.
             if !inside_negation {
-                sequence.push(Component::Namespace(Namespace {
-                    prefix: None,
-                    url: url
-                }));
+                sequence.push(Component::DefaultNamespace(url))
             }
         }
     } else {
@@ -1554,13 +1644,61 @@ pub mod tests {
         assert_eq!(parse(":lang(4)"), Err(())) ;
         assert_eq!(parse(":lang(en US)"), Err(())) ;
         assert_eq!(parse("EeÉ"), Ok(SelectorList(vec!(Selector {
-            inner: SelectorInner::from_vec(vec!(Component::LocalName(LocalName {
+            inner: SelectorInner::from_vec(vec!(
+                Component::LocalName(LocalName {
                     name: DummyAtom::from("EeÉ"),
-                    lower_name: DummyAtom::from("eeÉ") })),
-            ),
+                    lower_name: DummyAtom::from("eeÉ")
+                }),
+            )),
             pseudo_element: None,
             specificity: specificity(0, 0, 1),
         }))));
+        assert_eq!(parse("|e"), Ok(SelectorList(vec!(Selector {
+            inner: SelectorInner::from_vec(vec!(
+                Component::ExplicitNoNamespace,
+                Component::LocalName(LocalName {
+                    name: DummyAtom::from("e"),
+                    lower_name: DummyAtom::from("e")
+                }),
+            )),
+            pseudo_element: None,
+            specificity: specificity(0, 0, 1),
+        }))));
+        // https://github.com/servo/servo/issues/16020
+        assert_eq!(parse("*|e"), Ok(SelectorList(vec!(Selector {
+            inner: SelectorInner::from_vec(vec!(
+                Component::ExplicitAnyNamespace,
+                Component::LocalName(LocalName {
+                    name: DummyAtom::from("e"),
+                    lower_name: DummyAtom::from("e")
+                }),
+            )),
+            pseudo_element: None,
+            specificity: specificity(0, 0, 1),
+        }))));
+        assert_eq!(parse("*"), Ok(SelectorList(vec!(Selector {
+            inner: SelectorInner::from_vec(vec!(
+                Component::ExplicitUniversalType,
+            )),
+            pseudo_element: None,
+            specificity: specificity(0, 0, 0),
+        }))));
+        assert_eq!(parse("|*"), Ok(SelectorList(vec!(Selector {
+            inner: SelectorInner::from_vec(vec!(
+                Component::ExplicitNoNamespace,
+                Component::ExplicitUniversalType,
+            )),
+            pseudo_element: None,
+            specificity: specificity(0, 0, 0),
+        }))));
+        assert_eq!(parse("*|*"), Ok(SelectorList(vec!(Selector {
+            inner: SelectorInner::from_vec(vec!(
+                Component::ExplicitAnyNamespace,
+                Component::ExplicitUniversalType,
+            )),
+            pseudo_element: None,
+            specificity: specificity(0, 0, 0),
+        }))));
         assert_eq!(parse(".foo:lang(en-US)"), Ok(SelectorList(vec!(Selector {
             inner: SelectorInner::from_vec(vec![
                     Component::Class(DummyAtom::from("foo")),
@@ -1616,10 +1754,7 @@ pub mod tests {
         assert_eq!(parse_ns("svg|circle", &parser), Ok(SelectorList(vec![Selector {
             inner: SelectorInner::from_vec(
                 vec![
-                    Component::Namespace(Namespace {
-                        prefix: Some(DummyAtom("svg".into())),
-                        url: SVG.into(),
-                    }),
+                    Component::Namespace(DummyAtom("svg".into()), SVG.into()),
                     Component::LocalName(LocalName {
                         name: DummyAtom::from("circle"),
                         lower_name: DummyAtom::from("circle"),
@@ -1628,6 +1763,15 @@ pub mod tests {
             pseudo_element: None,
             specificity: specificity(0, 0, 1),
         }])));
+        assert_eq!(parse_ns("svg|*", &parser), Ok(SelectorList(vec![Selector {
+            inner: SelectorInner::from_vec(
+                vec![
+                    Component::Namespace(DummyAtom("svg".into()), SVG.into()),
+                    Component::ExplicitUniversalType,
+                ]),
+            pseudo_element: None,
+            specificity: specificity(0, 0, 0),
+        }])));
         // Default namespace does not apply to attribute selectors
         // https://github.com/mozilla/servo/pull/1652
         // but it does apply to implicit type selectors
@@ -1636,10 +1780,7 @@ pub mod tests {
         assert_eq!(parse_ns("[Foo]", &parser), Ok(SelectorList(vec!(Selector {
             inner: SelectorInner::from_vec(
                 vec![
-                    Component::Namespace(Namespace {
-                        prefix: None,
-                        url: MATHML.into(),
-                    }),
+                    Component::DefaultNamespace(MATHML.into()),
                     Component::AttrExists(AttrSelector {
                         name: DummyAtom::from("Foo"),
                         lower_name: DummyAtom::from("foo"),
@@ -1656,10 +1797,7 @@ pub mod tests {
         assert_eq!(parse_ns("e", &parser), Ok(SelectorList(vec!(Selector {
             inner: SelectorInner::from_vec(
                 vec!(
-                    Component::Namespace(Namespace {
-                        prefix: None,
-                        url: MATHML.into(),
-                    }),
+                    Component::DefaultNamespace(MATHML.into()),
                     Component::LocalName(LocalName {
                         name: DummyAtom::from("e"),
                         lower_name: DummyAtom::from("e") }),
@@ -1667,6 +1805,61 @@ pub mod tests {
             pseudo_element: None,
             specificity: specificity(0, 0, 1),
         }))));
+        assert_eq!(parse_ns("*", &parser), Ok(SelectorList(vec!(Selector {
+            inner: SelectorInner::from_vec(
+                vec!(
+                    Component::DefaultNamespace(MATHML.into()),
+                    Component::ExplicitUniversalType,
+                )),
+            pseudo_element: None,
+            specificity: specificity(0, 0, 0),
+        }))));
+        assert_eq!(parse_ns("*|*", &parser), Ok(SelectorList(vec!(Selector {
+            inner: SelectorInner::from_vec(
+                vec!(
+                    Component::ExplicitAnyNamespace,
+                    Component::ExplicitUniversalType,
+                )),
+            pseudo_element: None,
+            specificity: specificity(0, 0, 0),
+        }))));
+        // Default namespace applies to universal and type selectors inside :not and :matches,
+        // but not otherwise.
+        assert_eq!(parse_ns(":not(.cl)", &parser), Ok(SelectorList(vec!(Selector {
+            inner: SelectorInner::from_vec(vec!(
+                Component::DefaultNamespace(MATHML.into()),
+                Component::Negation(vec![
+                    Component::Class(DummyAtom::from("cl"))
+                ].into_boxed_slice()),
+            )),
+            pseudo_element: None,
+            specificity: specificity(0, 1, 0),
+        }))));
+        assert_eq!(parse_ns(":not(*)", &parser), Ok(SelectorList(vec!(Selector {
+            inner: SelectorInner::from_vec(vec!(
+                Component::DefaultNamespace(MATHML.into()),
+                Component::Negation(vec![
+                    Component::DefaultNamespace(MATHML.into()),
+                    Component::ExplicitUniversalType,
+                ].into_boxed_slice()),
+            )),
+            pseudo_element: None,
+            specificity: specificity(0, 0, 0),
+        }))));
+        assert_eq!(parse_ns(":not(e)", &parser), Ok(SelectorList(vec!(Selector {
+            inner: SelectorInner::from_vec(vec!(
+                Component::DefaultNamespace(MATHML.into()),
+                Component::Negation(vec![
+                    Component::DefaultNamespace(MATHML.into()),
+                    Component::LocalName(LocalName {
+                        name: DummyAtom::from("e"),
+                        lower_name: DummyAtom::from("e")
+                    }),
+                ].into_boxed_slice())
+            )),
+            pseudo_element: None,
+            specificity: specificity(0, 0, 1),
+        }))));
         assert_eq!(parse("[attr |= \"foo\"]"), Ok(SelectorList(vec![Selector {
             inner: SelectorInner::from_vec(
                 vec![
@@ -1727,10 +1920,7 @@ pub mod tests {
         assert_eq!(parse_ns(":not(svg|circle)", &parser), Ok(SelectorList(vec!(Selector {
             inner: SelectorInner::from_vec(vec!(Component::Negation(
                 vec![
-                    Component::Namespace(Namespace {
-                        prefix: Some(DummyAtom("svg".into())),
-                        url: SVG.into(),
-                    }),
+                    Component::Namespace(DummyAtom("svg".into()), SVG.into()),
                     Component::LocalName(LocalName {
                         name: DummyAtom::from("circle"),
                         lower_name: DummyAtom::from("circle")
@@ -1740,6 +1930,46 @@ pub mod tests {
             pseudo_element: None,
             specificity: specificity(0, 0, 1),
         }))));
+        // https://github.com/servo/servo/issues/16017
+        assert_eq!(parse_ns(":not(*)", &parser), Ok(SelectorList(vec!(Selector {
+            inner: SelectorInner::from_vec(vec!(Component::Negation(
+                vec![
+                    Component::ExplicitUniversalType,
+                ].into_boxed_slice()
+            ))),
+            pseudo_element: None,
+            specificity: specificity(0, 0, 0),
+        }))));
+        assert_eq!(parse_ns(":not(|*)", &parser), Ok(SelectorList(vec!(Selector {
+            inner: SelectorInner::from_vec(vec!(Component::Negation(
+                vec![
+                    Component::ExplicitNoNamespace,
+                    Component::ExplicitUniversalType,
+                ].into_boxed_slice()
+            ))),
+            pseudo_element: None,
+            specificity: specificity(0, 0, 0),
+        }))));
+        assert_eq!(parse_ns(":not(*|*)", &parser), Ok(SelectorList(vec!(Selector {
+            inner: SelectorInner::from_vec(vec!(Component::Negation(
+                vec![
+                    Component::ExplicitAnyNamespace,
+                    Component::ExplicitUniversalType,
+                ].into_boxed_slice()
+            ))),
+            pseudo_element: None,
+            specificity: specificity(0, 0, 0),
+        }))));
+        assert_eq!(parse_ns(":not(svg|*)", &parser), Ok(SelectorList(vec!(Selector {
+            inner: SelectorInner::from_vec(vec!(Component::Negation(
+                vec![
+                    Component::Namespace(DummyAtom("svg".into()), SVG.into()),
+                    Component::ExplicitUniversalType,
+                ].into_boxed_slice()
+            ))),
+            pseudo_element: None,
+            specificity: specificity(0, 0, 0),
+        }))));
     }
 
     struct TestVisitor {
diff --git a/components/style/stylist.rs b/components/style/stylist.rs
index 74221045b11..acef07d054e 100644
--- a/components/style/stylist.rs
+++ b/components/style/stylist.rs
@@ -1359,8 +1359,8 @@ impl SelectorMap<Rule> {
 
         let mut rules_list = vec![];
         for rule in self.other.iter() {
-            if rule.selector.inner.complex.iter_raw().next().is_none() {
-                rules_list.push(rule.to_applicable_declaration_block(cascade_level));
+            if rule.selector.is_universal() {
+                rules_list.push(rule.to_applicable_declaration_block(cascade_level))
             }
         }
 
diff --git a/tests/unit/style/stylesheets.rs b/tests/unit/style/stylesheets.rs
index 1cef0f377be..81d8a6fffd4 100644
--- a/tests/unit/style/stylesheets.rs
+++ b/tests/unit/style/stylesheets.rs
@@ -92,10 +92,7 @@ fn test_parse_stylesheet() {
                 selectors: SelectorList(vec![
                     Selector {
                         inner: SelectorInner::from_vec(vec![
-                            Component::Namespace(Namespace {
-                                prefix: None,
-                                url: NsAtom::from("http://www.w3.org/1999/xhtml")
-                            }),
+                            Component::DefaultNamespace(NsAtom::from("http://www.w3.org/1999/xhtml")),
                             Component::LocalName(LocalName {
                                 name: local_name!("input"),
                                 lower_name: local_name!("input"),
@@ -129,10 +126,7 @@ fn test_parse_stylesheet() {
                 selectors: SelectorList(vec![
                     Selector {
                         inner: SelectorInner::from_vec(vec![
-                            Component::Namespace(Namespace {
-                                prefix: None,
-                                url: NsAtom::from("http://www.w3.org/1999/xhtml")
-                            }),
+                            Component::DefaultNamespace(NsAtom::from("http://www.w3.org/1999/xhtml")),
                             Component::LocalName(LocalName {
                                 name: local_name!("html"),
                                 lower_name: local_name!("html"),
@@ -143,10 +137,7 @@ fn test_parse_stylesheet() {
                     },
                     Selector {
                         inner: SelectorInner::from_vec(vec![
-                            Component::Namespace(Namespace {
-                                prefix: None,
-                                url: NsAtom::from("http://www.w3.org/1999/xhtml")
-                            }),
+                            Component::DefaultNamespace(NsAtom::from("http://www.w3.org/1999/xhtml")),
                             Component::LocalName(LocalName {
                                 name: local_name!("body"),
                                 lower_name: local_name!("body"),
@@ -169,16 +160,10 @@ fn test_parse_stylesheet() {
                 selectors: SelectorList(vec![
                     Selector {
                         inner: SelectorInner::from_vec(vec![
-                            Component::Namespace(Namespace {
-                                prefix: None,
-                                url: NsAtom::from("http://www.w3.org/1999/xhtml")
-                            }),
+                            Component::DefaultNamespace(NsAtom::from("http://www.w3.org/1999/xhtml")),
                             Component::ID(Atom::from("d1")),
                             Component::Combinator(Combinator::Child),
-                            Component::Namespace(Namespace {
-                                prefix: None,
-                                url: NsAtom::from("http://www.w3.org/1999/xhtml")
-                            }),
+                            Component::DefaultNamespace(NsAtom::from("http://www.w3.org/1999/xhtml")),
                             Component::Class(Atom::from("ok")),
                         ]),
                         pseudo_element: None,
diff --git a/tests/unit/style/stylist.rs b/tests/unit/style/stylist.rs
index 073c003b0bb..3c136edcef3 100644
--- a/tests/unit/style/stylist.rs
+++ b/tests/unit/style/stylist.rs
@@ -212,9 +212,9 @@ fn test_insert() {
 #[test]
 fn test_get_universal_rules() {
     thread_state::initialize(thread_state::LAYOUT);
-    let (map, shared_lock) = get_mock_map(&["*|*", "#foo > *|*", ".klass", "#id"]);
+    let (map, shared_lock) = get_mock_map(&["*|*", "#foo > *|*", "*|* > *|*", ".klass", "#id"]);
 
     let decls = map.get_universal_rules(CascadeLevel::UserNormal);
 
-    assert_eq!(decls.len(), 1);
+    assert_eq!(decls.len(), 1, "{:?}", decls);
 }