Bug 1357357 - Make the parser of transition-property match the spec.

1. We add a new arm to TransitionProperty, TransitionProperty::Unsupported,
   which contains an Atom, so it's better to remove the Copy trait from
   TransitionProperty.
2. TransitionProperty::Unsupported(Atom) represents any non-animatable, custom,
   or unrecognized property, and we use Atom to store the ident string for
   serialization.

13 files changed, 139 insertions, 56 deletions

diff --git a/components/style/animation.rs b/components/style/animation.rs
index 2229d485591..16c7dab364d 100644
--- a/components/style/animation.rs
+++ b/components/style/animation.rs
@@ -272,9 +272,13 @@ impl PropertyAnimation {
         let timing_function = box_style.transition_timing_function_mod(transition_index);
         let duration = box_style.transition_duration_mod(transition_index);
 
+        if let TransitionProperty::Unsupported(_) = transition_property {
+            return result
+        }
+
         if transition_property.is_shorthand() {
             return transition_property.longhands().iter().filter_map(|transition_property| {
-                PropertyAnimation::from_transition_property(*transition_property,
+                PropertyAnimation::from_transition_property(transition_property,
                                                             timing_function,
                                                             duration,
                                                             old_style,
@@ -284,7 +288,7 @@ impl PropertyAnimation {
 
         if transition_property != TransitionProperty::All {
             if let Some(property_animation) =
-                    PropertyAnimation::from_transition_property(transition_property,
+                    PropertyAnimation::from_transition_property(&transition_property,
                                                                 timing_function,
                                                                 duration,
                                                                 old_style,
@@ -296,7 +300,7 @@ impl PropertyAnimation {
 
         TransitionProperty::each(|transition_property| {
             if let Some(property_animation) =
-                    PropertyAnimation::from_transition_property(transition_property,
+                    PropertyAnimation::from_transition_property(&transition_property,
                                                                 timing_function,
                                                                 duration,
                                                                 old_style,
@@ -308,15 +312,15 @@ impl PropertyAnimation {
         result
     }
 
-    fn from_transition_property(transition_property: TransitionProperty,
+    fn from_transition_property(transition_property: &TransitionProperty,
                                 timing_function: TransitionTimingFunction,
                                 duration: Time,
                                 old_style: &ComputedValues,
                                 new_style: &ComputedValues)
                                 -> Option<PropertyAnimation> {
         debug_assert!(!transition_property.is_shorthand() &&
-                      transition_property != TransitionProperty::All);
-        let animated_property = AnimatedProperty::from_transition_property(&transition_property,
+                      transition_property != &TransitionProperty::All);
+        let animated_property = AnimatedProperty::from_transition_property(transition_property,
                                                                            old_style,
                                                                            new_style);
 
@@ -702,7 +706,7 @@ pub fn update_style_for_animation(context: &SharedStyleContext,
             for transition_property in &animation.properties_changed {
                 debug!("update_style_for_animation: scanning prop {:?} for animation \"{}\"",
                        transition_property, name);
-                match PropertyAnimation::from_transition_property(*transition_property,
+                match PropertyAnimation::from_transition_property(transition_property,
                                                                   timing_function,
                                                                   Time::from_seconds(relative_duration as f32),
                                                                   &from_style,
diff --git a/components/style/build_gecko.rs b/components/style/build_gecko.rs
index 00aac6d8526..9d170e64105 100644
--- a/components/style/build_gecko.rs
+++ b/components/style/build_gecko.rs
@@ -659,6 +659,7 @@ mod bindings {
             "StyleBasicShape",
             "StyleBasicShapeType",
             "StyleShapeSource",
+            "StyleTransition",
             "nsCSSFontFaceRule",
             "nsCSSKeyword",
             "nsCSSPropertyID",
diff --git a/components/style/dom.rs b/components/style/dom.rs
index ffc9f67ef8d..645db055be7 100644
--- a/components/style/dom.rs
+++ b/components/style/dom.rs
@@ -520,7 +520,7 @@ pub trait TElement : Eq + PartialEq + Debug + Hash + Sized + Copy + Clone +
     /// Returns true if we need to update transitions for the specified property on this element.
     #[cfg(feature = "gecko")]
     fn needs_transitions_update_per_property(&self,
-                                             property: TransitionProperty,
+                                             property: &TransitionProperty,
                                              combined_duration: f32,
                                              before_change_style: &Arc<ComputedValues>,
                                              after_change_style: &Arc<ComputedValues>,
diff --git a/components/style/gecko/wrapper.rs b/components/style/gecko/wrapper.rs
index 6c72aa0b3d5..948a87d4cf6 100644
--- a/components/style/gecko/wrapper.rs
+++ b/components/style/gecko/wrapper.rs
@@ -811,7 +811,7 @@ impl<'le> TElement for GeckoElement<'le> {
                 continue;
             }
 
-            let mut property_check_helper = |property: TransitionProperty| -> bool {
+            let mut property_check_helper = |property: &TransitionProperty| -> bool {
                 if self.needs_transitions_update_per_property(property,
                                                               combined_duration,
                                                               before_change_style,
@@ -821,7 +821,9 @@ impl<'le> TElement for GeckoElement<'le> {
                 }
 
                 if let Some(set) = transitions_to_keep.as_mut() {
-                    set.insert(property);
+                    // The TransitionProperty here must be animatable, so cloning it is cheap
+                    // because it is an integer-like enum.
+                    set.insert(property.clone());
                 }
                 false
             };
@@ -835,12 +837,12 @@ impl<'le> TElement for GeckoElement<'le> {
                 });
                 if is_shorthand {
                     let shorthand: TransitionProperty = property.into();
-                    if shorthand.longhands().iter().any(|&p| property_check_helper(p)) {
+                    if shorthand.longhands().iter().any(|p| property_check_helper(p)) {
                         return true;
                     }
                 } else {
                     if animated_properties::nscsspropertyid_is_animatable(property) &&
-                       property_check_helper(property.into()) {
+                       property_check_helper(&property.into()) {
                         return true;
                     }
                 }
@@ -855,7 +857,7 @@ impl<'le> TElement for GeckoElement<'le> {
     }
 
     fn needs_transitions_update_per_property(&self,
-                                             property: TransitionProperty,
+                                             property: &TransitionProperty,
                                              combined_duration: f32,
                                              before_change_style: &Arc<ComputedValues>,
                                              after_change_style: &Arc<ComputedValues>,
@@ -869,17 +871,17 @@ impl<'le> TElement for GeckoElement<'le> {
             return false;
         }
 
-        if existing_transitions.contains_key(&property) {
+        if existing_transitions.contains_key(property) {
             // If there is an existing transition, update only if the end value differs.
             // If the end value has not changed, we should leave the currently running
             // transition as-is since we don't want to interrupt its timing function.
             let after_value =
-                Arc::new(AnimationValue::from_computed_values(&property, after_change_style));
-            return existing_transitions.get(&property).unwrap() != &after_value;
+                Arc::new(AnimationValue::from_computed_values(property, after_change_style));
+            return existing_transitions.get(property).unwrap() != &after_value;
         }
 
         combined_duration > 0.0f32 &&
-        AnimatedProperty::from_transition_property(&property,
+        AnimatedProperty::from_transition_property(property,
                                                    before_change_style,
                                                    after_change_style).does_animate()
     }
diff --git a/components/style/gecko_bindings/bindings.rs b/components/style/gecko_bindings/bindings.rs
index c663df92012..f4d1a515d4b 100644
--- a/components/style/gecko_bindings/bindings.rs
+++ b/components/style/gecko_bindings/bindings.rs
@@ -39,6 +39,7 @@ use gecko_bindings::structs::SheetParsingMode;
 use gecko_bindings::structs::StyleBasicShape;
 use gecko_bindings::structs::StyleBasicShapeType;
 use gecko_bindings::structs::StyleShapeSource;
+use gecko_bindings::structs::StyleTransition;
 use gecko_bindings::structs::nsCSSFontFaceRule;
 use gecko_bindings::structs::nsCSSKeyword;
 use gecko_bindings::structs::nsCSSPropertyID;
@@ -693,6 +694,11 @@ extern "C" {
      -> RawServoAnimationValueBorrowedOrNull;
 }
 extern "C" {
+    pub fn Gecko_StyleTransition_SetUnsupportedProperty(aTransition:
+                                                            *mut StyleTransition,
+                                                        aAtom: *mut nsIAtom);
+}
+extern "C" {
     pub fn Gecko_Atomize(aString: *const ::std::os::raw::c_char, aLength: u32)
      -> *mut nsIAtom;
 }
diff --git a/components/style/keyframes.rs b/components/style/keyframes.rs
index d7e3485fc7d..fb8290fedf4 100644
--- a/components/style/keyframes.rs
+++ b/components/style/keyframes.rs
@@ -259,8 +259,8 @@ fn get_animated_properties(keyframes: &[Arc<Locked<Keyframe>>], guard: &SharedRw
 
             if let Some(property) = TransitionProperty::from_declaration(declaration) {
                 if !seen.has_transition_property_bit(&property) {
-                    ret.push(property);
                     seen.set_transition_property_bit(&property);
+                    ret.push(property);
                 }
             }
         }
diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
index 57ebd1114ff..fc40dcff52d 100644
--- a/components/style/properties/gecko.mako.rs
+++ b/components/style/properties/gecko.mako.rs
@@ -33,6 +33,7 @@ use gecko_bindings::bindings::Gecko_FontFamilyList_AppendNamed;
 use gecko_bindings::bindings::Gecko_FontFamilyList_Clear;
 use gecko_bindings::bindings::Gecko_SetCursorArrayLength;
 use gecko_bindings::bindings::Gecko_SetCursorImage;
+use gecko_bindings::bindings::Gecko_StyleTransition_SetUnsupportedProperty;
 use gecko_bindings::bindings::Gecko_NewCSSShadowArray;
 use gecko_bindings::bindings::Gecko_nsStyleFont_SetLang;
 use gecko_bindings::bindings::Gecko_nsStyleFont_CopyLangFrom;
@@ -53,6 +54,7 @@ use gecko::values::convert_rgba_to_nscolor;
 use gecko::values::GeckoStyleCoordConvertible;
 use gecko::values::round_border_to_device_pixels;
 use logical_geometry::WritingMode;
+use properties::animated_properties::TransitionProperty;
 use properties::longhands;
 use properties::{Importance, LonghandId};
 use properties::{PropertyDeclaration, PropertyDeclarationBlock, PropertyDeclarationId};
@@ -2149,7 +2151,12 @@ fn static_assert() {
             unsafe { self.gecko.mTransitions.ensure_len(v.0.len()) };
             self.gecko.mTransitionPropertyCount = v.0.len() as u32;
             for (servo, gecko) in v.0.into_iter().zip(self.gecko.mTransitions.iter_mut()) {
-                gecko.mProperty = servo.into();
+                match servo {
+                    TransitionProperty::Unsupported(ref atom) => unsafe {
+                        Gecko_StyleTransition_SetUnsupportedProperty(gecko, atom.as_ptr())
+                    },
+                    _ => gecko.mProperty = (&servo).into(),
+                }
             }
         } else {
             // In gecko |none| is represented by eCSSPropertyExtra_no_properties.
@@ -2172,7 +2179,22 @@ fn static_assert() {
 
     pub fn transition_property_at(&self, index: usize)
         -> longhands::transition_property::computed_value::SingleComputedValue {
-        self.gecko.mTransitions[index].mProperty.into()
+        use gecko_bindings::structs::nsCSSPropertyID::eCSSPropertyExtra_no_properties;
+        use gecko_bindings::structs::nsCSSPropertyID::eCSSPropertyExtra_variable;
+        use gecko_bindings::structs::nsCSSPropertyID::eCSSProperty_UNKNOWN;
+
+        let property = self.gecko.mTransitions[index].mProperty;
+        if property == eCSSProperty_UNKNOWN || property == eCSSPropertyExtra_variable {
+            let atom = self.gecko.mTransitions[index].mUnknownProperty.raw();
+            debug_assert!(!atom.is_null());
+            TransitionProperty::Unsupported(atom.into())
+        } else if property == eCSSPropertyExtra_no_properties {
+            // Actually, we don't expect TransitionProperty::Unsupported also represents "none",
+            // but if the caller wants to convert it, it is fine. Please use it carefully.
+            TransitionProperty::Unsupported(atom!("none"))
+        } else {
+            property.into()
+        }
     }
 
     pub fn transition_nscsspropertyid_at(&self, index: usize) -> nsCSSPropertyID {
@@ -2180,6 +2202,8 @@ fn static_assert() {
     }
 
     pub fn copy_transition_property_from(&mut self, other: &Self) {
+        use gecko_bindings::structs::nsCSSPropertyID::eCSSPropertyExtra_variable;
+        use gecko_bindings::structs::nsCSSPropertyID::eCSSProperty_UNKNOWN;
         unsafe { self.gecko.mTransitions.ensure_len(other.gecko.mTransitions.len()) };
 
         let count = other.gecko.mTransitionPropertyCount;
@@ -2187,6 +2211,12 @@ fn static_assert() {
 
         for (index, transition) in self.gecko.mTransitions.iter_mut().enumerate().take(count as usize) {
             transition.mProperty = other.gecko.mTransitions[index].mProperty;
+            if transition.mProperty == eCSSProperty_UNKNOWN ||
+               transition.mProperty == eCSSPropertyExtra_variable {
+                let atom = other.gecko.mTransitions[index].mUnknownProperty.raw();
+                debug_assert!(!atom.is_null());
+                unsafe { Gecko_StyleTransition_SetUnsupportedProperty(transition, atom) };
+            }
         }
     }
     ${impl_transition_count('property', 'Property')}
diff --git a/components/style/properties/helpers/animated_properties.mako.rs b/components/style/properties/helpers/animated_properties.mako.rs
index 8783fc4a44f..cd384da294a 100644
--- a/components/style/properties/helpers/animated_properties.mako.rs
+++ b/components/style/properties/helpers/animated_properties.mako.rs
@@ -7,9 +7,10 @@
 <% from data import SYSTEM_FONT_LONGHANDS %>
 
 use app_units::Au;
-use cssparser::{Color as CSSParserColor, Parser, RGBA};
+use cssparser::{Color as CSSParserColor, Parser, RGBA, serialize_identifier};
 use euclid::{Point2D, Size2D};
 #[cfg(feature = "gecko")] use gecko_bindings::structs::nsCSSPropertyID;
+#[cfg(feature = "gecko")] use gecko_string_cache::Atom;
 use properties::{CSSWideKeyword, PropertyDeclaration};
 use properties::longhands;
 use properties::longhands::background_size::computed_value::T as BackgroundSizeList;
@@ -25,6 +26,7 @@ use properties::longhands::transform::computed_value::T as TransformList;
 use properties::longhands::vertical_align::computed_value::T as VerticalAlign;
 use properties::longhands::visibility::computed_value::T as Visibility;
 #[cfg(feature = "gecko")] use properties::{PropertyDeclarationId, LonghandId};
+#[cfg(feature = "servo")] use servo_atoms::Atom;
 use std::cmp;
 #[cfg(feature = "gecko")] use std::collections::HashMap;
 use std::fmt;
@@ -45,7 +47,7 @@ use values::generics::position as generic_position;
 /// property.
 // NB: This needs to be here because it needs all the longhands generated
 // beforehand.
-#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
 pub enum TransitionProperty {
     /// All, any animatable property changing should generate a transition.
@@ -62,24 +64,27 @@ pub enum TransitionProperty {
         /// ${prop.name}
         ${prop.camel_case},
     % endfor
+    /// Unrecognized property which could be any non-animatable, custom property, or
+    /// unknown property.
+    Unsupported(Atom)
 }
 
 impl TransitionProperty {
     /// Iterates over each longhand property.
-    pub fn each<F: FnMut(TransitionProperty) -> ()>(mut cb: F) {
+    pub fn each<F: FnMut(&TransitionProperty) -> ()>(mut cb: F) {
         % for prop in data.longhands:
             % if prop.animatable:
-                cb(TransitionProperty::${prop.camel_case});
+                cb(&TransitionProperty::${prop.camel_case});
             % endif
         % endfor
     }
 
     /// Iterates over every property that is not TransitionProperty::All, stopping and returning
     /// true when the provided callback returns true for the first time.
-    pub fn any<F: FnMut(TransitionProperty) -> bool>(mut cb: F) -> bool {
+    pub fn any<F: FnMut(&TransitionProperty) -> bool>(mut cb: F) -> bool {
         % for prop in data.longhands:
             % if prop.animatable:
-                if cb(TransitionProperty::${prop.camel_case}) {
+                if cb(&TransitionProperty::${prop.camel_case}) {
                     return true;
                 }
             % endif
@@ -89,7 +94,8 @@ impl TransitionProperty {
 
     /// Parse a transition-property value.
     pub fn parse(input: &mut Parser) -> Result<Self, ()> {
-        match_ignore_ascii_case! { &try!(input.expect_ident()),
+        let ident = try!(input.expect_ident());
+        match_ignore_ascii_case! { &ident,
             "all" => Ok(TransitionProperty::All),
             % for prop in data.longhands:
                 % if prop.animatable:
@@ -99,7 +105,13 @@ impl TransitionProperty {
             % for prop in data.shorthands_except_all():
                 "${prop.name}" => Ok(TransitionProperty::${prop.camel_case}),
             % endfor
-            _ => Err(())
+            "none" => Err(()),
+            _ => {
+                match CSSWideKeyword::from_ident(&ident) {
+                    Some(_) => Err(()),
+                    None => Ok(TransitionProperty::Unsupported((&*ident).into()))
+                }
+            }
         }
     }
 
@@ -199,6 +211,11 @@ impl ToCss for TransitionProperty {
             % for prop in data.shorthands_except_all():
                 TransitionProperty::${prop.camel_case} => dest.write_str("${prop.name}"),
             % endfor
+            #[cfg(feature = "gecko")]
+            TransitionProperty::Unsupported(ref atom) => serialize_identifier(&atom.to_string(),
+                                                                              dest),
+            #[cfg(feature = "servo")]
+            TransitionProperty::Unsupported(ref atom) => serialize_identifier(atom, dest),
         }
     }
 }
@@ -206,9 +223,9 @@ impl ToCss for TransitionProperty {
 /// Convert to nsCSSPropertyID.
 #[cfg(feature = "gecko")]
 #[allow(non_upper_case_globals)]
-impl From<TransitionProperty> for nsCSSPropertyID {
-    fn from(transition_property: TransitionProperty) -> nsCSSPropertyID {
-        match transition_property {
+impl<'a> From< &'a TransitionProperty> for nsCSSPropertyID {
+    fn from(transition_property: &'a TransitionProperty) -> nsCSSPropertyID {
+        match *transition_property {
             % for prop in data.longhands:
                 % if prop.animatable:
                     TransitionProperty::${prop.camel_case}
@@ -220,6 +237,7 @@ impl From<TransitionProperty> for nsCSSPropertyID {
                     => ${helpers.to_nscsspropertyid(prop.ident)},
             % endfor
             TransitionProperty::All => nsCSSPropertyID::eCSSPropertyExtra_all_properties,
+            _ => panic!("Unconvertable Servo transition property: {:?}", transition_property),
         }
     }
 }
@@ -234,6 +252,9 @@ impl From<nsCSSPropertyID> for TransitionProperty {
                 % if prop.animatable:
                     ${helpers.to_nscsspropertyid(prop.ident)}
                         => TransitionProperty::${prop.camel_case},
+                % else:
+                    ${helpers.to_nscsspropertyid(prop.ident)}
+                        => TransitionProperty::Unsupported(Atom::from("${prop.ident}")),
                 % endif
             % endfor
             % for prop in data.shorthands_except_all():
@@ -241,7 +262,7 @@ impl From<nsCSSPropertyID> for TransitionProperty {
                     => TransitionProperty::${prop.camel_case},
             % endfor
             nsCSSPropertyID::eCSSPropertyExtra_all_properties => TransitionProperty::All,
-            _ => panic!("Unsupported Servo transition property: {:?}", property),
+            _ => panic!("Unconvertable nsCSSPropertyID: {:?}", property),
         }
     }
 }
@@ -356,7 +377,7 @@ impl AnimatedProperty {
                     }
                 % endif
             % endfor
-            other => panic!("Can't use TransitionProperty::{:?} here", other),
+            ref other => panic!("Can't use TransitionProperty::{:?} here", other),
         }
     }
 }
@@ -544,7 +565,7 @@ impl AnimationValue {
                     }
                 % endif
             % endfor
-            other => panic!("Can't use TransitionProperty::{:?} here.", other),
+            ref other => panic!("Can't use TransitionProperty::{:?} here.", other),
         }
     }
 }
diff --git a/components/style/properties/properties.mako.rs b/components/style/properties/properties.mako.rs
index 69932549fe2..fa6ed21a33b 100644
--- a/components/style/properties/properties.mako.rs
+++ b/components/style/properties/properties.mako.rs
@@ -258,7 +258,7 @@ impl LonghandIdSet {
                     TransitionProperty::${prop.camel_case} => self.insert(LonghandId::${prop.camel_case}),
                 % endif
             % endfor
-            other => unreachable!("Tried to set TransitionProperty::{:?} in a PropertyBitfield", other),
+            ref other => unreachable!("Tried to set TransitionProperty::{:?} in a PropertyBitfield", other),
         }
     }
 
@@ -271,7 +271,7 @@ impl LonghandIdSet {
                     TransitionProperty::${prop.camel_case} => self.contains(LonghandId::${prop.camel_case}),
                 % endif
             % endfor
-            other => unreachable!("Tried to get TransitionProperty::{:?} in a PropertyBitfield", other),
+            ref other => unreachable!("Tried to get TransitionProperty::{:?} in a PropertyBitfield", other),
         }
     }
 }
diff --git a/components/style/properties/shorthand/box.mako.rs b/components/style/properties/shorthand/box.mako.rs
index cf98bffa347..0dd320735a8 100644
--- a/components/style/properties/shorthand/box.mako.rs
+++ b/components/style/properties/shorthand/box.mako.rs
@@ -98,10 +98,12 @@ macro_rules! try_parse_one {
             loop {
                 parsed += 1;
 
-                try_parse_one!(input, property, transition_property);
                 try_parse_one!(context, input, duration, transition_duration);
                 try_parse_one!(context, input, timing_function, transition_timing_function);
                 try_parse_one!(context, input, delay, transition_delay);
+                // Must check 'transition-property' after 'transition-timing-function' since
+                // 'transition-property' accepts any keyword.
+                try_parse_one!(input, property, transition_property);
 
                 parsed -= 1;
                 break
diff --git a/ports/geckolib/glue.rs b/ports/geckolib/glue.rs
index 0366a05aa83..7e463db9d13 100644
--- a/ports/geckolib/glue.rs
+++ b/ports/geckolib/glue.rs
@@ -1985,7 +1985,7 @@ pub extern "C" fn Servo_GetComputedKeyframeValues(keyframes: RawGeckoKeyframeLis
                     // This is safe since we immediately write to the uninitialized values.
                     unsafe { animation_values.set_len((i + 1) as u32) };
                     seen.set_transition_property_bit(&anim.0);
-                    animation_values[i].mProperty = anim.0.into();
+                    animation_values[i].mProperty = (&anim.0).into();
                     // We only make sure we have enough space for this variable,
                     // but didn't construct a default value for StyleAnimationValue,
                     // so we should zero it to avoid getting undefined behaviors.
@@ -2056,7 +2056,7 @@ pub extern "C" fn Servo_StyleSet_FillKeyframesForName(raw_data: RawServoStyleSet
                 let block = style.to_declaration_block(property.clone().into());
                 unsafe {
                     (*keyframe).mPropertyValues.set_len((index + 1) as u32);
-                    (*keyframe).mPropertyValues[index].mProperty = property.clone().into();
+                    (*keyframe).mPropertyValues[index].mProperty = property.into();
                     // FIXME. Do not set computed values once we handles missing keyframes
                     // with additive composition.
                     (*keyframe).mPropertyValues[index].mServoDeclarationBlock.set_arc_leaky(
@@ -2087,7 +2087,7 @@ pub extern "C" fn Servo_StyleSet_FillKeyframesForName(raw_data: RawServoStyleSet
                         unsafe {
                             let property = TransitionProperty::from_declaration(declaration).unwrap();
                             (*keyframe).mPropertyValues.set_len((index + 1) as u32);
-                            (*keyframe).mPropertyValues[index].mProperty = property.into();
+                            (*keyframe).mPropertyValues[index].mProperty = (&property).into();
                             (*keyframe).mPropertyValues[index].mServoDeclarationBlock.set_arc_leaky(
                                 Arc::new(global_style_data.shared_lock.wrap(
                                   PropertyDeclarationBlock::with_one(
diff --git a/tests/unit/style/parsing/transition_property.rs b/tests/unit/style/parsing/transition_property.rs
index 5283f173afc..5929489651c 100644
--- a/tests/unit/style/parsing/transition_property.rs
+++ b/tests/unit/style/parsing/transition_property.rs
@@ -3,6 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use parsing::parse;
+use servo_atoms::Atom;
 use style::properties::animated_properties::TransitionProperty;
 use style::properties::longhands::transition_property;
 use style::properties::shorthands::transition;
@@ -13,16 +14,21 @@ fn test_longhand_properties() {
     assert_roundtrip_with_context!(transition_property::parse, "margin-left");
     assert_roundtrip_with_context!(transition_property::parse, "background-color");
     assert_roundtrip_with_context!(transition_property::parse, "width");
+    assert_roundtrip_with_context!(transition_property::parse, "transition-duration");
+    assert_roundtrip_with_context!(transition_property::parse, "unsupported-property");
+    assert_roundtrip_with_context!(transition_property::parse, "-other-unsupported-property");
+    assert_roundtrip_with_context!(transition_property::parse, "--var");
 
-    assert_eq!(parse_longhand!(transition_property, "margin-left, width"),
+    assert_eq!(parse_longhand!(transition_property, "margin-left, transition-delay, width, --var"),
                transition_property::SpecifiedValue(
                    vec![TransitionProperty::MarginLeft,
-                        TransitionProperty::Width]));
+                        TransitionProperty::Unsupported(Atom::from("transition-delay")),
+                        TransitionProperty::Width,
+                        TransitionProperty::Unsupported(Atom::from("--var"))]));
 
-    // TODO: If one of the identifiers listed is not a recognized property name or is not an
-    // animatable property, the implementation must still start transitions on the animatable
-    // properties. Therefore, the parser shouldn't return Err for non-animatable property.
-    assert!(parse(transition_property::parse, "transition-duration").is_err());
+    assert!(parse(transition_property::parse, ".width").is_err());
+    assert!(parse(transition_property::parse, "1width").is_err());
+    assert!(parse(transition_property::parse, "- ").is_err());
 }
 
 #[test]
@@ -44,11 +50,22 @@ fn test_keywords() {
 
     assert_eq!(parse_longhand!(transition_property, "all"),
                transition_property::SpecifiedValue(vec![TransitionProperty::All]));
+    assert_eq!(parse_longhand!(transition_property, "width, all"),
+               transition_property::SpecifiedValue(vec![TransitionProperty::Width,
+                                                        TransitionProperty::All]));
+
+    // Using CSS Wide Keyword or none in the list will get the syntax invalid.
+    // Note: Only "none" alone is valid.
+    assert!(parse(transition_property::parse, "none").is_ok());
     assert_eq!(parse_longhand!(transition_property, "none"),
                transition_property::SpecifiedValue(vec![]));
-
     assert!(parse(transition_property::parse, "inherit").is_err());
     assert!(parse(transition_property::parse, "initial").is_err());
+    assert!(parse(transition_property::parse, "unset").is_err());
+    assert!(parse(transition_property::parse, "width, none").is_err());
+    assert!(parse(transition_property::parse, "width, initial").is_err());
+    assert!(parse(transition_property::parse, "width, inherit").is_err());
+    assert!(parse(transition_property::parse, "width, unset").is_err());
 }
 
 #[test]
@@ -61,7 +78,16 @@ fn test_transition_shorthand() {
     assert_eq!(result.transition_property,
                parse_longhand!(transition_property, "margin, all"));
 
+    let result = parse(transition::parse_value, "2s width, 3s --var, 4s background").unwrap();
+    assert_eq!(result.transition_property,
+               parse_longhand!(transition_property, "width, --var, background"));
+
     let result = parse(transition::parse_value, "none").unwrap();
     assert_eq!(result.transition_property,
                parse_longhand!(transition_property, "none"));
+
+    assert!(parse(transition::parse_value, "2s width, none").is_err());
+    assert!(parse(transition::parse_value, "2s width, 2s initial").is_err());
+    assert!(parse(transition::parse_value, "2s width, 3s unset").is_err());
+    assert!(parse(transition::parse_value, "2s width, 4s inherit").is_err());
 }
diff --git a/tests/wpt/metadata-css/css-transitions-1_dev/html/transition-property-002.htm.ini b/tests/wpt/metadata-css/css-transitions-1_dev/html/transition-property-002.htm.ini
index d32a55f8927..701a4cb902f 100644
--- a/tests/wpt/metadata-css/css-transitions-1_dev/html/transition-property-002.htm.ini
+++ b/tests/wpt/metadata-css/css-transitions-1_dev/html/transition-property-002.htm.ini
@@ -6,15 +6,6 @@
   [parse 'all, none']
     expected: FAIL
 
-  [parse 'foobar']
-    expected: FAIL
-
-  [parse 'all, foobar']
-    expected: FAIL
-
-  [parse 'foobar, all']
-    expected: FAIL
-
   [parse 'initial']
     expected: FAIL