Auto merge of #28629 - emirror-de:cssparser-0.29, r=emilio

Updated cssparser dependency to 0.29.

Signed-off-by: Lewin Probst <info@emirror.de>

This commit updates the cssparser dependency to 0.29. The intention is to get the selectors crate to cssparser 0.29. This will reduce problems in other crates that belong on both, selectors and cssparser.

Would love to get a review and changes required to be able to merge this.

---
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18 files changed, 78 insertions, 81 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 21af7a0014f..85b3f55a297 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1192,9 +1192,9 @@ dependencies = [
 
 [[package]]
 name = "cssparser"
-version = "0.28.1"
+version = "0.29.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1db8599a9761b371751fbf13e076fa03c6e1a78f8c5288e6ab9467f10a2322c1"
+checksum = "2a3a85949f6cbf49a4e1ab98a98e0f9aabfe7d827a7f156da36c98a86dede2df"
 dependencies = [
  "cssparser-macros",
  "dtoa-short",
diff --git a/components/canvas/Cargo.toml b/components/canvas/Cargo.toml
index 3d02f0ee42f..04b5e1162ee 100644
--- a/components/canvas/Cargo.toml
+++ b/components/canvas/Cargo.toml
@@ -20,7 +20,7 @@ bitflags = "1.0"
 byteorder = "1"
 canvas_traits = { path = "../canvas_traits" }
 crossbeam-channel = "0.4"
-cssparser = "0.28"
+cssparser = "0.29"
 euclid = "0.20"
 font-kit = "0.10"
 fnv = "1.0"
diff --git a/components/canvas_traits/Cargo.toml b/components/canvas_traits/Cargo.toml
index 8e0d3397c25..499d8c43399 100644
--- a/components/canvas_traits/Cargo.toml
+++ b/components/canvas_traits/Cargo.toml
@@ -16,7 +16,7 @@ xr-profile = ["webxr-api/profile", "time"]
 
 [dependencies]
 crossbeam-channel = "0.4"
-cssparser = "0.28"
+cssparser = "0.29"
 euclid = "0.20"
 ipc-channel = "0.14"
 lazy_static = "1"
diff --git a/components/layout_2020/Cargo.toml b/components/layout_2020/Cargo.toml
index 24e3ead663b..d32cdc90e39 100644
--- a/components/layout_2020/Cargo.toml
+++ b/components/layout_2020/Cargo.toml
@@ -16,7 +16,7 @@ doctest = false
 app_units = "0.7"
 atomic_refcell = "0.1.6"
 canvas_traits = { path = "../canvas_traits" }
-cssparser = "0.28"
+cssparser = "0.29"
 embedder_traits = { path = "../embedder_traits" }
 euclid = "0.20"
 fnv = "1.0"
diff --git a/components/malloc_size_of/Cargo.toml b/components/malloc_size_of/Cargo.toml
index 97e60e16d7e..8ee174d013f 100644
--- a/components/malloc_size_of/Cargo.toml
+++ b/components/malloc_size_of/Cargo.toml
@@ -31,7 +31,7 @@ accountable-refcell = { version = "0.2.0", optional = true }
 app_units = "0.7"
 content-security-policy = { version = "0.4.0", features = ["serde"], optional = true }
 crossbeam-channel = { version = "0.4", optional = true }
-cssparser = "0.28"
+cssparser = "0.29"
 euclid = "0.20"
 hashglobe = { path = "../hashglobe" }
 hyper = { version = "0.12", optional = true }
diff --git a/components/script/Cargo.toml b/components/script/Cargo.toml
index 7e9fc2dbb07..1c9464db740 100644
--- a/components/script/Cargo.toml
+++ b/components/script/Cargo.toml
@@ -42,7 +42,7 @@ chrono = "0.4"
 content-security-policy = { version = "0.4.0", features = ["serde"] }
 cookie = "0.11"
 crossbeam-channel = "0.4"
-cssparser = "0.28"
+cssparser = "0.29"
 data-url = "0.1.0"
 deny_public_fields = { path = "../deny_public_fields" }
 devtools_traits = { path = "../devtools_traits" }
diff --git a/components/selectors/Cargo.toml b/components/selectors/Cargo.toml
index facd2983bbd..3701b311d4b 100644
--- a/components/selectors/Cargo.toml
+++ b/components/selectors/Cargo.toml
@@ -19,7 +19,7 @@ bench = []
 
 [dependencies]
 bitflags = "1.0"
-cssparser = "0.28"
+cssparser = "0.29"
 derive_more = "0.99"
 fxhash = "0.2"
 log = "0.4"
diff --git a/components/style/Cargo.toml b/components/style/Cargo.toml
index e0539bab343..218229774b6 100644
--- a/components/style/Cargo.toml
+++ b/components/style/Cargo.toml
@@ -35,7 +35,7 @@ arrayvec = "0.5"
 atomic_refcell = "0.1"
 bitflags = "1.0"
 byteorder = "1.0"
-cssparser = "0.28"
+cssparser = "0.29"
 derive_more = "0.99"
 encoding_rs = { version = "0.8", optional = true }
 euclid = "0.20"
diff --git a/components/style/counter_style/mod.rs b/components/style/counter_style/mod.rs
index 5effa11bcdd..1688189d3e0 100644
--- a/components/style/counter_style/mod.rs
+++ b/components/style/counter_style/mod.rs
@@ -143,8 +143,7 @@ struct CounterStyleRuleParser<'a, 'b: 'a> {
 
 /// Default methods reject all at rules.
 impl<'a, 'b, 'i> AtRuleParser<'i> for CounterStyleRuleParser<'a, 'b> {
-    type PreludeNoBlock = ();
-    type PreludeBlock = ();
+    type Prelude = ();
     type AtRule = ();
     type Error = StyleParseErrorKind<'i>;
 }
diff --git a/components/style/font_face.rs b/components/style/font_face.rs
index 24204efc131..884978c5c3b 100644
--- a/components/style/font_face.rs
+++ b/components/style/font_face.rs
@@ -371,8 +371,7 @@ struct FontFaceRuleParser<'a, 'b: 'a> {
 
 /// Default methods reject all at rules.
 impl<'a, 'b, 'i> AtRuleParser<'i> for FontFaceRuleParser<'a, 'b> {
-    type PreludeNoBlock = ();
-    type PreludeBlock = ();
+    type Prelude = ();
     type AtRule = ();
     type Error = StyleParseErrorKind<'i>;
 }
diff --git a/components/style/properties/declaration_block.rs b/components/style/properties/declaration_block.rs
index fd41c1141cb..3639ae24f6e 100644
--- a/components/style/properties/declaration_block.rs
+++ b/components/style/properties/declaration_block.rs
@@ -44,7 +44,6 @@ impl AnimationDeclarations {
     }
 }
 
-
 /// An enum describes how a declaration should update
 /// the declaration block.
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
@@ -838,7 +837,7 @@ impl PropertyDeclarationBlock {
                         custom_properties.as_ref(),
                         QuirksMode::NoQuirks,
                         device,
-                        &mut Default::default()
+                        &mut Default::default(),
                     )
                     .to_css(dest)
             },
@@ -884,10 +883,7 @@ impl PropertyDeclarationBlock {
         &self,
         context: &Context,
     ) -> Option<Arc<crate::custom_properties::CustomPropertiesMap>> {
-        self.cascade_custom_properties(
-            context.style().custom_properties(),
-            context.device(),
-        )
+        self.cascade_custom_properties(context.style().custom_properties(), context.device())
     }
 
     /// Returns a custom properties map which is the result of cascading custom
@@ -1080,9 +1076,15 @@ impl PropertyDeclarationBlock {
                 // AppendableValue::Css.
                 let mut v = CssString::new();
                 let value = match appendable_value {
-                    AppendableValue::Css { css, with_variables } => {
+                    AppendableValue::Css {
+                        css,
+                        with_variables,
+                    } => {
                         debug_assert!(!css.is_empty());
-                        AppendableValue::Css { css, with_variables }
+                        AppendableValue::Css {
+                            css,
+                            with_variables,
+                        }
                     },
                     other => {
                         append_declaration_value(&mut v, other)?;
@@ -1354,8 +1356,7 @@ struct PropertyDeclarationParser<'a, 'b: 'a> {
 
 /// Default methods reject all at rules.
 impl<'a, 'b, 'i> AtRuleParser<'i> for PropertyDeclarationParser<'a, 'b> {
-    type PreludeNoBlock = ();
-    type PreludeBlock = ();
+    type Prelude = ();
     type AtRule = Importance;
     type Error = StyleParseErrorKind<'i>;
 }
diff --git a/components/style/stylesheets/font_feature_values_rule.rs b/components/style/stylesheets/font_feature_values_rule.rs
index 98eef923f7e..dc9e9f333db 100644
--- a/components/style/stylesheets/font_feature_values_rule.rs
+++ b/components/style/stylesheets/font_feature_values_rule.rs
@@ -18,7 +18,7 @@ use crate::stylesheets::CssRuleType;
 use crate::values::computed::font::FamilyName;
 use crate::values::serialize_atom_identifier;
 use crate::Atom;
-use cssparser::{AtRuleParser, AtRuleType, BasicParseErrorKind, CowRcStr};
+use cssparser::{AtRuleParser, BasicParseErrorKind, CowRcStr};
 use cssparser::{DeclarationListParser, DeclarationParser, Parser};
 use cssparser::{ParserState, QualifiedRuleParser, RuleListParser, SourceLocation, Token};
 use std::fmt::{self, Write};
@@ -188,8 +188,7 @@ struct FFVDeclarationsParser<'a, 'b: 'a, T: 'a> {
 
 /// Default methods reject all at rules.
 impl<'a, 'b, 'i, T> AtRuleParser<'i> for FFVDeclarationsParser<'a, 'b, T> {
-    type PreludeNoBlock = ();
-    type PreludeBlock = ();
+    type Prelude = ();
     type AtRule = ();
     type Error = StyleParseErrorKind<'i>;
 }
@@ -393,18 +392,17 @@ macro_rules! font_feature_values_blocks {
         }
 
         impl<'a, 'i> AtRuleParser<'i> for FontFeatureValuesRuleParser<'a> {
-            type PreludeNoBlock = ();
-            type PreludeBlock = BlockType;
+            type Prelude = BlockType;
             type AtRule = ();
             type Error = StyleParseErrorKind<'i>;
 
             fn parse_prelude<'t>(&mut self,
                                  name: CowRcStr<'i>,
                                  input: &mut Parser<'i, 't>)
-                                 -> Result<AtRuleType<(), BlockType>, ParseError<'i>> {
+                                 -> Result<Self::Prelude, ParseError<'i>> {
                 match_ignore_ascii_case! { &*name,
                     $(
-                        $name => Ok(AtRuleType::WithBlock(BlockType::$ident_camel)),
+                        $name => Ok(Self::Prelude::$ident_camel),
                     )*
                     _ => Err(input.new_error(BasicParseErrorKind::AtRuleBodyInvalid)),
                 }
diff --git a/components/style/stylesheets/keyframes_rule.rs b/components/style/stylesheets/keyframes_rule.rs
index ad53ac6d667..374f6f1d8ec 100644
--- a/components/style/stylesheets/keyframes_rule.rs
+++ b/components/style/stylesheets/keyframes_rule.rs
@@ -505,8 +505,7 @@ pub fn parse_keyframe_list(
 }
 
 impl<'a, 'i> AtRuleParser<'i> for KeyframeListParser<'a> {
-    type PreludeNoBlock = ();
-    type PreludeBlock = ();
+    type Prelude = ();
     type AtRule = Arc<Locked<Keyframe>>;
     type Error = StyleParseErrorKind<'i>;
 }
@@ -580,8 +579,7 @@ struct KeyframeDeclarationParser<'a, 'b: 'a> {
 
 /// Default methods reject all at rules.
 impl<'a, 'b, 'i> AtRuleParser<'i> for KeyframeDeclarationParser<'a, 'b> {
-    type PreludeNoBlock = ();
-    type PreludeBlock = ();
+    type Prelude = ();
     type AtRule = ();
     type Error = StyleParseErrorKind<'i>;
 }
diff --git a/components/style/stylesheets/rule_parser.rs b/components/style/stylesheets/rule_parser.rs
index df4a2c0631c..524d54d9c33 100644
--- a/components/style/stylesheets/rule_parser.rs
+++ b/components/style/stylesheets/rule_parser.rs
@@ -26,8 +26,10 @@ use crate::stylesheets::{NamespaceRule, PageRule, StyleRule, SupportsRule, Viewp
 use crate::values::computed::font::FamilyName;
 use crate::values::{CssUrl, CustomIdent, KeyframesName};
 use crate::{Namespace, Prefix};
-use cssparser::{AtRuleParser, AtRuleType, Parser, QualifiedRuleParser, RuleListParser};
-use cssparser::{BasicParseError, BasicParseErrorKind, CowRcStr, ParserState, SourcePosition};
+use cssparser::{AtRuleParser, Parser, QualifiedRuleParser, RuleListParser};
+use cssparser::{
+    BasicParseError, BasicParseErrorKind, CowRcStr, ParseErrorKind, ParserState, SourcePosition,
+};
 use selectors::SelectorList;
 use servo_arc::Arc;
 use style_traits::{ParseError, StyleParseErrorKind};
@@ -146,7 +148,7 @@ pub enum VendorPrefix {
 }
 
 /// A rule prelude for at-rule with block.
-pub enum AtRuleBlockPrelude {
+pub enum AtRulePrelude {
     /// A @font-face rule prelude.
     FontFace,
     /// A @font-feature-values rule prelude, with its FamilyName list.
@@ -165,10 +167,6 @@ pub enum AtRuleBlockPrelude {
     Page,
     /// A @document rule, with its conditional.
     Document(DocumentCondition),
-}
-
-/// A rule prelude for at-rule without block.
-pub enum AtRuleNonBlockPrelude {
     /// A @import rule prelude.
     Import(CssUrl, Arc<Locked<MediaList>>),
     /// A @namespace rule prelude.
@@ -176,8 +174,7 @@ pub enum AtRuleNonBlockPrelude {
 }
 
 impl<'a, 'i> AtRuleParser<'i> for TopLevelRuleParser<'a> {
-    type PreludeNoBlock = AtRuleNonBlockPrelude;
-    type PreludeBlock = AtRuleBlockPrelude;
+    type Prelude = AtRulePrelude;
     type AtRule = (SourcePosition, CssRule);
     type Error = StyleParseErrorKind<'i>;
 
@@ -185,7 +182,7 @@ impl<'a, 'i> AtRuleParser<'i> for TopLevelRuleParser<'a> {
         &mut self,
         name: CowRcStr<'i>,
         input: &mut Parser<'i, 't>,
-    ) -> Result<AtRuleType<AtRuleNonBlockPrelude, AtRuleBlockPrelude>, ParseError<'i>> {
+    ) -> Result<Self::Prelude, ParseError<'i>> {
         match_ignore_ascii_case! { &*name,
             "import" => {
                 if !self.check_state(State::Imports) {
@@ -209,9 +206,9 @@ impl<'a, 'i> AtRuleParser<'i> for TopLevelRuleParser<'a> {
                 let media = MediaList::parse(&self.context, input);
                 let media = Arc::new(self.shared_lock.wrap(media));
 
-                let prelude = AtRuleNonBlockPrelude::Import(url, media);
+                let prelude = AtRulePrelude::Import(url, media);
 
-                return Ok(AtRuleType::WithoutBlock(prelude));
+                return Ok(prelude);
             },
             "namespace" => {
                 if !self.check_state(State::Namespaces) {
@@ -228,8 +225,8 @@ impl<'a, 'i> AtRuleParser<'i> for TopLevelRuleParser<'a> {
                     Err(e) => return Err(e.into()),
                 };
                 let url = Namespace::from(maybe_namespace.as_ref());
-                let prelude = AtRuleNonBlockPrelude::Namespace(prefix, url);
-                return Ok(AtRuleType::WithoutBlock(prelude));
+                let prelude = AtRulePrelude::Namespace(prefix, url);
+                return Ok(prelude);
             },
             // @charset is removed by rust-cssparser if it’s the first rule in the stylesheet
             // anything left is invalid.
@@ -250,7 +247,7 @@ impl<'a, 'i> AtRuleParser<'i> for TopLevelRuleParser<'a> {
     #[inline]
     fn parse_block<'t>(
         &mut self,
-        prelude: AtRuleBlockPrelude,
+        prelude: AtRulePrelude,
         start: &ParserState,
         input: &mut Parser<'i, 't>,
     ) -> Result<Self::AtRule, ParseError<'i>> {
@@ -262,11 +259,11 @@ impl<'a, 'i> AtRuleParser<'i> for TopLevelRuleParser<'a> {
     #[inline]
     fn rule_without_block(
         &mut self,
-        prelude: AtRuleNonBlockPrelude,
+        prelude: AtRulePrelude,
         start: &ParserState,
-    ) -> Self::AtRule {
+    ) -> Result<Self::AtRule, ()> {
         let rule = match prelude {
-            AtRuleNonBlockPrelude::Import(url, media) => {
+            AtRulePrelude::Import(url, media) => {
                 let loader = self
                     .loader
                     .expect("Expected a stylesheet loader for @import");
@@ -282,7 +279,7 @@ impl<'a, 'i> AtRuleParser<'i> for TopLevelRuleParser<'a> {
                 self.state = State::Imports;
                 CssRule::Import(import_rule)
             },
-            AtRuleNonBlockPrelude::Namespace(prefix, url) => {
+            AtRulePrelude::Namespace(prefix, url) => {
                 let prefix = if let Some(prefix) = prefix {
                     self.namespaces.prefixes.insert(prefix.clone(), url.clone());
                     Some(prefix)
@@ -298,9 +295,10 @@ impl<'a, 'i> AtRuleParser<'i> for TopLevelRuleParser<'a> {
                     source_location: start.source_location(),
                 })))
             },
+            _ => return Err(()),
         };
 
-        (start.position(), rule)
+        Ok((start.position(), rule))
     }
 }
 
@@ -372,8 +370,7 @@ impl<'a, 'b> NestedRuleParser<'a, 'b> {
 }
 
 impl<'a, 'b, 'i> AtRuleParser<'i> for NestedRuleParser<'a, 'b> {
-    type PreludeNoBlock = AtRuleNonBlockPrelude;
-    type PreludeBlock = AtRuleBlockPrelude;
+    type Prelude = AtRulePrelude;
     type AtRule = CssRule;
     type Error = StyleParseErrorKind<'i>;
 
@@ -381,19 +378,19 @@ impl<'a, 'b, 'i> AtRuleParser<'i> for NestedRuleParser<'a, 'b> {
         &mut self,
         name: CowRcStr<'i>,
         input: &mut Parser<'i, 't>,
-    ) -> Result<AtRuleType<AtRuleNonBlockPrelude, AtRuleBlockPrelude>, ParseError<'i>> {
+    ) -> Result<Self::Prelude, ParseError<'i>> {
         match_ignore_ascii_case! { &*name,
             "media" => {
                 let media_queries = MediaList::parse(self.context, input);
                 let arc = Arc::new(self.shared_lock.wrap(media_queries));
-                Ok(AtRuleType::WithBlock(AtRuleBlockPrelude::Media(arc)))
+                Ok(Self::Prelude::Media(arc))
             },
             "supports" => {
                 let cond = SupportsCondition::parse(input)?;
-                Ok(AtRuleType::WithBlock(AtRuleBlockPrelude::Supports(cond)))
+                Ok(Self::Prelude::Supports(cond))
             },
             "font-face" => {
-                Ok(AtRuleType::WithBlock(AtRuleBlockPrelude::FontFace))
+                Ok(Self::Prelude::FontFace)
             },
             "font-feature-values" => {
                 if !cfg!(feature = "gecko") {
@@ -401,7 +398,7 @@ impl<'a, 'b, 'i> AtRuleParser<'i> for NestedRuleParser<'a, 'b> {
                     return Err(input.new_custom_error(StyleParseErrorKind::UnsupportedAtRule(name.clone())))
                 }
                 let family_names = parse_family_name_list(self.context, input)?;
-                Ok(AtRuleType::WithBlock(AtRuleBlockPrelude::FontFeatureValues(family_names)))
+                Ok(Self::Prelude::FontFeatureValues(family_names))
             },
             "counter-style" => {
                 if !cfg!(feature = "gecko") {
@@ -409,11 +406,11 @@ impl<'a, 'b, 'i> AtRuleParser<'i> for NestedRuleParser<'a, 'b> {
                     return Err(input.new_custom_error(StyleParseErrorKind::UnsupportedAtRule(name.clone())))
                 }
                 let name = parse_counter_style_name_definition(input)?;
-                Ok(AtRuleType::WithBlock(AtRuleBlockPrelude::CounterStyle(name)))
+                Ok(Self::Prelude::CounterStyle(name))
             },
             "viewport" => {
                 if viewport_rule::enabled() {
-                    Ok(AtRuleType::WithBlock(AtRuleBlockPrelude::Viewport))
+                    Ok(Self::Prelude::Viewport)
                 } else {
                     Err(input.new_custom_error(StyleParseErrorKind::UnsupportedAtRule(name.clone())))
                 }
@@ -433,11 +430,11 @@ impl<'a, 'b, 'i> AtRuleParser<'i> for NestedRuleParser<'a, 'b> {
                 }
                 let name = KeyframesName::parse(self.context, input)?;
 
-                Ok(AtRuleType::WithBlock(AtRuleBlockPrelude::Keyframes(name, prefix)))
+                Ok(Self::Prelude::Keyframes(name, prefix))
             },
             "page" => {
                 if cfg!(feature = "gecko") {
-                    Ok(AtRuleType::WithBlock(AtRuleBlockPrelude::Page))
+                    Ok(Self::Prelude::Page)
                 } else {
                     Err(input.new_custom_error(StyleParseErrorKind::UnsupportedAtRule(name.clone())))
                 }
@@ -450,7 +447,7 @@ impl<'a, 'b, 'i> AtRuleParser<'i> for NestedRuleParser<'a, 'b> {
                 }
 
                 let cond = DocumentCondition::parse(self.context, input)?;
-                Ok(AtRuleType::WithBlock(AtRuleBlockPrelude::Document(cond)))
+                Ok(Self::Prelude::Document(cond))
             },
             _ => Err(input.new_custom_error(StyleParseErrorKind::UnsupportedAtRule(name.clone())))
         }
@@ -458,12 +455,12 @@ impl<'a, 'b, 'i> AtRuleParser<'i> for NestedRuleParser<'a, 'b> {
 
     fn parse_block<'t>(
         &mut self,
-        prelude: AtRuleBlockPrelude,
+        prelude: AtRulePrelude,
         start: &ParserState,
         input: &mut Parser<'i, 't>,
     ) -> Result<CssRule, ParseError<'i>> {
         match prelude {
-            AtRuleBlockPrelude::FontFace => {
+            AtRulePrelude::FontFace => {
                 let context = ParserContext::new_with_rule_type(
                     self.context,
                     CssRuleType::FontFace,
@@ -474,7 +471,7 @@ impl<'a, 'b, 'i> AtRuleParser<'i> for NestedRuleParser<'a, 'b> {
                     parse_font_face_block(&context, input, start.source_location()).into(),
                 ))))
             },
-            AtRuleBlockPrelude::FontFeatureValues(family_names) => {
+            AtRulePrelude::FontFeatureValues(family_names) => {
                 let context = ParserContext::new_with_rule_type(
                     self.context,
                     CssRuleType::FontFeatureValues,
@@ -490,7 +487,7 @@ impl<'a, 'b, 'i> AtRuleParser<'i> for NestedRuleParser<'a, 'b> {
                     ),
                 ))))
             },
-            AtRuleBlockPrelude::CounterStyle(name) => {
+            AtRulePrelude::CounterStyle(name) => {
                 let context = ParserContext::new_with_rule_type(
                     self.context,
                     CssRuleType::CounterStyle,
@@ -504,14 +501,14 @@ impl<'a, 'b, 'i> AtRuleParser<'i> for NestedRuleParser<'a, 'b> {
                     ),
                 )))
             },
-            AtRuleBlockPrelude::Media(media_queries) => {
+            AtRulePrelude::Media(media_queries) => {
                 Ok(CssRule::Media(Arc::new(self.shared_lock.wrap(MediaRule {
                     media_queries,
                     rules: self.parse_nested_rules(input, CssRuleType::Media),
                     source_location: start.source_location(),
                 }))))
             },
-            AtRuleBlockPrelude::Supports(condition) => {
+            AtRulePrelude::Supports(condition) => {
                 let eval_context = ParserContext::new_with_rule_type(
                     self.context,
                     CssRuleType::Style,
@@ -528,7 +525,7 @@ impl<'a, 'b, 'i> AtRuleParser<'i> for NestedRuleParser<'a, 'b> {
                     },
                 ))))
             },
-            AtRuleBlockPrelude::Viewport => {
+            AtRulePrelude::Viewport => {
                 let context = ParserContext::new_with_rule_type(
                     self.context,
                     CssRuleType::Viewport,
@@ -539,7 +536,7 @@ impl<'a, 'b, 'i> AtRuleParser<'i> for NestedRuleParser<'a, 'b> {
                     self.shared_lock.wrap(ViewportRule::parse(&context, input)?),
                 )))
             },
-            AtRuleBlockPrelude::Keyframes(name, vendor_prefix) => {
+            AtRulePrelude::Keyframes(name, vendor_prefix) => {
                 let context = ParserContext::new_with_rule_type(
                     self.context,
                     CssRuleType::Keyframes,
@@ -555,7 +552,7 @@ impl<'a, 'b, 'i> AtRuleParser<'i> for NestedRuleParser<'a, 'b> {
                     },
                 ))))
             },
-            AtRuleBlockPrelude::Page => {
+            AtRulePrelude::Page => {
                 let context = ParserContext::new_with_rule_type(
                     self.context,
                     CssRuleType::Page,
@@ -568,7 +565,7 @@ impl<'a, 'b, 'i> AtRuleParser<'i> for NestedRuleParser<'a, 'b> {
                     source_location: start.source_location(),
                 }))))
             },
-            AtRuleBlockPrelude::Document(condition) => {
+            AtRulePrelude::Document(condition) => {
                 if !cfg!(feature = "gecko") {
                     unreachable!()
                 }
@@ -580,6 +577,12 @@ impl<'a, 'b, 'i> AtRuleParser<'i> for NestedRuleParser<'a, 'b> {
                     },
                 ))))
             },
+            _ => Err(ParseError {
+                kind: ParseErrorKind::Basic(BasicParseErrorKind::AtRuleInvalid(CowRcStr::from(
+                    "Unsupported AtRule Prelude.",
+                ))),
+                location: start.source_location(),
+            }),
         }
     }
 }
diff --git a/components/style/stylesheets/viewport_rule.rs b/components/style/stylesheets/viewport_rule.rs
index a1090636bf0..9f751ece265 100644
--- a/components/style/stylesheets/viewport_rule.rs
+++ b/components/style/stylesheets/viewport_rule.rs
@@ -241,8 +241,7 @@ fn parse_shorthand<'i, 't>(
 }
 
 impl<'a, 'b, 'i> AtRuleParser<'i> for ViewportRuleParser<'a, 'b> {
-    type PreludeNoBlock = ();
-    type PreludeBlock = ();
+    type Prelude = ();
     type AtRule = Vec<ViewportDescriptorDeclaration>;
     type Error = StyleParseErrorKind<'i>;
 }
diff --git a/components/style_traits/Cargo.toml b/components/style_traits/Cargo.toml
index 02bee7d899c..693698b441b 100644
--- a/components/style_traits/Cargo.toml
+++ b/components/style_traits/Cargo.toml
@@ -16,7 +16,7 @@ gecko = []
 [dependencies]
 app_units = "0.7"
 bitflags = "1.0"
-cssparser = "0.28"
+cssparser = "0.29"
 euclid = "0.20"
 lazy_static = "1"
 malloc_size_of = { path = "../malloc_size_of" }
diff --git a/components/to_shmem/Cargo.toml b/components/to_shmem/Cargo.toml
index 6027d2670e6..ca1fd8675a1 100644
--- a/components/to_shmem/Cargo.toml
+++ b/components/to_shmem/Cargo.toml
@@ -14,7 +14,7 @@ servo = ["cssparser/serde", "string_cache"]
 gecko = []
 
 [dependencies]
-cssparser = "0.28"
+cssparser = "0.29"
 servo_arc = { path = "../servo_arc" }
 smallbitvec = "2.1.1"
 smallvec = "1.0"
diff --git a/tests/unit/style/Cargo.toml b/tests/unit/style/Cargo.toml
index 51056e378f4..51660774900 100644
--- a/tests/unit/style/Cargo.toml
+++ b/tests/unit/style/Cargo.toml
@@ -11,7 +11,7 @@ doctest = false
 
 [dependencies]
 app_units = "0.7"
-cssparser = "0.28"
+cssparser = "0.29"
 euclid = "0.20"
 html5ever = "0.25"
 rayon = "1"