Auto merge of #17981 - heycam:family-serialization, r=emilio

style: Preserve font-family identifier sequence when serializing.

Reviewed by Emilio in https://bugzilla.mozilla.org/show_bug.cgi?id=1384398.

components/style/properties/gecko.mako.rs

@@ -2181,7 +2181,7 @@ fn static_assert() {
     }
 
     pub fn set_font_family(&mut self, v: longhands::font_family::computed_value::T) {
-        use properties::longhands::font_family::computed_value::FontFamily;
+        use properties::longhands::font_family::computed_value::{FontFamily, FamilyNameSyntax};
 
         let list = &mut self.gecko.mFont.fontlist;
         unsafe { Gecko_FontFamilyList_Clear(list); }
@@ -2191,7 +2191,8 @@ fn static_assert() {
         for family in &v.0 {
             match *family {
                 FontFamily::FamilyName(ref f) => {
-                    unsafe { Gecko_FontFamilyList_AppendNamed(list, f.name.as_ptr(), f.quoted); }
+                    let quoted = matches!(f.syntax, FamilyNameSyntax::Quoted);
+                    unsafe { Gecko_FontFamilyList_AppendNamed(list, f.name.as_ptr(), quoted); }
                 }
                 FontFamily::Generic(ref name) => {
                     let (family_type, generic) = FontFamily::generic(name);
@@ -2222,7 +2223,8 @@ fn static_assert() {
     }
 
     pub fn clone_font_family(&self) -> longhands::font_family::computed_value::T {
-        use properties::longhands::font_family::computed_value::{FontFamily, FamilyName};
+        use cssparser::serialize_identifier;
+        use properties::longhands::font_family::computed_value::{FontFamily, FamilyName, FamilyNameSyntax};
         use gecko_bindings::structs::FontFamilyType;
         use gecko_string_cache::Atom;
 
@@ -2235,13 +2237,18 @@ fn static_assert() {
                     FontFamilyType::eFamily_cursive => FontFamily::Generic(atom!("cursive")),
                     FontFamilyType::eFamily_fantasy => FontFamily::Generic(atom!("fantasy")),
                     FontFamilyType::eFamily_moz_fixed => FontFamily::Generic(Atom::from("-moz-fixed")),
-                    FontFamilyType::eFamily_named => FontFamily::FamilyName(FamilyName {
-                        name: (&*gecko_font_family_name.mName).into(),
-                        quoted: false
-                    }),
+                    FontFamilyType::eFamily_named => {
+                        let name = Atom::from(&*gecko_font_family_name.mName);
+                        let mut serialization = String::new();
+                        serialize_identifier(&name.to_string(), &mut serialization).unwrap();
+                        FontFamily::FamilyName(FamilyName {
+                            name: name.clone(),
+                            syntax: FamilyNameSyntax::Identifiers(serialization),
+                        })
+                    },
                     FontFamilyType::eFamily_named_quoted => FontFamily::FamilyName(FamilyName {
                         name: (&*gecko_font_family_name.mName).into(),
-                        quoted: true
+                        syntax: FamilyNameSyntax::Quoted,
                     }),
                     x => panic!("Found unexpected font FontFamilyType: {:?}", x),
                 }

components/style/properties/longhand/font.mako.rs

@@ -96,7 +96,20 @@ macro_rules! impl_gecko_keyword_conversions {
         #[cfg_attr(feature = "servo", derive(HeapSizeOf, Deserialize, Serialize))]
         pub struct FamilyName {
             pub name: Atom,
-            pub quoted: bool,
+            pub syntax: FamilyNameSyntax,
+        }
+
+        #[derive(Debug, PartialEq, Eq, Clone, Hash)]
+        #[cfg_attr(feature = "servo", derive(HeapSizeOf, Deserialize, Serialize))]
+        pub enum FamilyNameSyntax {
+            /// The family name was specified in a quoted form, e.g. "Font Name"
+            /// or 'Font Name'.
+            Quoted,
+
+            /// The family name was specified in an unquoted form as a sequence of
+            /// identifiers.  The `String` is the serialization of the sequence of
+            /// identifiers.
+            Identifiers(String),
         }
 
         impl FontFamily {
@@ -139,7 +152,7 @@ macro_rules! impl_gecko_keyword_conversions {
                 // quoted by default.
                 FontFamily::FamilyName(FamilyName {
                     name: input,
-                    quoted: true,
+                    syntax: FamilyNameSyntax::Quoted,
                 })
             }
 
@@ -148,7 +161,7 @@ macro_rules! impl_gecko_keyword_conversions {
                 if let Ok(value) = input.try(|i| i.expect_string_cloned()) {
                     return Ok(FontFamily::FamilyName(FamilyName {
                         name: Atom::from(&*value),
-                        quoted: true,
+                        syntax: FamilyNameSyntax::Quoted,
                     }))
                 }
                 let first_ident = input.expect_ident()?.clone();
@@ -182,20 +195,28 @@ macro_rules! impl_gecko_keyword_conversions {
                 }
 
                 let mut value = first_ident.as_ref().to_owned();
+                let mut serialization = String::new();
+                serialize_identifier(&first_ident, &mut serialization).unwrap();
+
                 // These keywords are not allowed by themselves.
                 // The only way this value can be valid with with another keyword.
                 if css_wide_keyword {
                     let ident = input.expect_ident()?;
-                    value.push_str(" ");
+                    value.push(' ');
                     value.push_str(&ident);
+                    serialization.push(' ');
+                    serialize_identifier(&ident, &mut serialization).unwrap();
                 }
                 while let Ok(ident) = input.try(|i| i.expect_ident_cloned()) {
-                    value.push_str(" ");
+                    value.push(' ');
                     value.push_str(&ident);
+                    serialization.push(' ');
+                    serialize_identifier(&ident, &mut serialization).unwrap();
                 }
+                println!("serialization: {}", serialization);
                 Ok(FontFamily::FamilyName(FamilyName {
                     name: Atom::from(value),
-                    quoted: false,
+                    syntax: FamilyNameSyntax::Identifiers(serialization),
                 }))
             }
 
@@ -229,12 +250,17 @@ macro_rules! impl_gecko_keyword_conversions {
 
         impl ToCss for FamilyName {
             fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
-                if self.quoted {
-                    dest.write_char('"')?;
-                    write!(CssStringWriter::new(dest), "{}", self.name)?;
-                    dest.write_char('"')
-                } else {
-                    serialize_identifier(&*self.name.to_string(), dest)
+                match self.syntax {
+                    FamilyNameSyntax::Quoted => {
+                        dest.write_char('"')?;
+                        write!(CssStringWriter::new(dest), "{}", self.name)?;
+                        dest.write_char('"')
+                    }
+                    FamilyNameSyntax::Identifiers(ref serialization) => {
+                        // Note that `serialization` is already escaped/
+                        // serialized appropriately.
+                        dest.write_str(&*serialization)
+                    }
                 }
             }
         }
@@ -2508,7 +2534,7 @@ ${helpers.single_keyword("-moz-math-variant",
                     use properties::longhands::font_family::computed_value::*;
                     FontFamily::FamilyName(FamilyName {
                         name: (&*font.mName).into(),
-                        quoted: true
+                        syntax: FamilyNameSyntax::Quoted,
                     })
                 }).collect::<Vec<_>>();
                 let weight = longhands::font_weight::computed_value::T::from_gecko_weight(system.weight);

tests/unit/gfx/font_cache_thread.rs

@@ -5,7 +5,7 @@
 use cssparser::SourceLocation;
 use gfx::font_cache_thread::FontCacheThread;
 use ipc_channel::ipc;
-use style::computed_values::font_family::FamilyName;
+use style::computed_values::font_family::{FamilyName, FamilyNameSyntax};
 use style::font_face::{FontFaceRuleData, Source};
 
 #[test]
@@ -15,11 +15,11 @@ fn test_local_web_font() {
     let font_cache_thread = FontCacheThread::new(inp_chan, None);
     let family_name = FamilyName {
         name: From::from("test family"),
-        quoted: true,
+        syntax: FamilyNameSyntax::Quoted,
     };
     let variant_name = FamilyName {
         name: From::from("test font face"),
-        quoted: true,
+        syntax: FamilyNameSyntax::Quoted,
     };
     let font_face_rule = FontFaceRuleData {
         family: Some(family_name.clone()),

tests/unit/style/stylesheets.rs

@@ -14,7 +14,7 @@ use servo_url::ServoUrl;
 use std::borrow::ToOwned;
 use std::sync::Mutex;
 use std::sync::atomic::AtomicBool;
-use style::computed_values::font_family::FamilyName;
+use style::computed_values::font_family::{FamilyName, FamilyNameSyntax};
 use style::context::QuirksMode;
 use style::error_reporting::{ParseErrorReporter, ContextualParseError};
 use style::media_queries::MediaList;
@@ -254,7 +254,7 @@ fn test_parse_stylesheet() {
                 CssRule::FontFeatureValues(Arc::new(stylesheet.shared_lock.wrap(FontFeatureValuesRule {
                     family_names: vec![FamilyName {
                         name: Atom::from("test"),
-                        quoted: false,
+                        syntax: FamilyNameSyntax::Identifiers(String::from("test")),
                     }],
                     swash: vec![
                         FFVDeclaration {