style: Custom properties with invalid variable references should be unset, not invalid.

See https://github.com/w3c/csswg-drafts/issues/4075.

There are tests that will get updated and this will make pass in bug 1623347.

Differential Revision: https://phabricator.services.mozilla.com/D67373
This commit is contained in:
Emilio Cobos Álvarez 2020-03-26 11:34:12 +00:00
parent e0b4619fa5
commit 3004286308

View file

@ -579,9 +579,10 @@ impl<'a> CustomPropertiesBuilder<'a> {
match result {
Ok(new_value) => Arc::new(new_value),
Err(..) => {
map.remove(name);
// Don't touch the map, this has the same effect as
// making it compute to the inherited one.
return;
},
}
}
} else {
(*unparsed_value).clone()
@ -653,16 +654,22 @@ impl<'a> CustomPropertiesBuilder<'a> {
None => return self.inherited.cloned(),
};
if self.may_have_cycles {
substitute_all(&mut map, self.device);
let inherited = self.inherited.as_ref().map(|m| &***m);
substitute_all(&mut map, inherited, self.device);
}
Some(Arc::new(map))
}
}
/// Resolve all custom properties to either substituted or invalid.
/// Resolve all custom properties to either substituted, invalid, or unset
/// (meaning we should use the inherited value).
///
/// It does cycle dependencies removal at the same time as substitution.
fn substitute_all(custom_properties_map: &mut CustomPropertiesMap, device: &Device) {
fn substitute_all(
custom_properties_map: &mut CustomPropertiesMap,
inherited: Option<&CustomPropertiesMap>,
device: &Device,
) {
// The cycle dependencies removal in this function is a variant
// of Tarjan's algorithm. It is mostly based on the pseudo-code
// listed in
@ -698,6 +705,9 @@ fn substitute_all(custom_properties_map: &mut CustomPropertiesMap, device: &Devi
/// all unfinished strong connected components.
stack: SmallVec<[usize; 5]>,
map: &'a mut CustomPropertiesMap,
/// The inherited variables. We may need to restore some if we fail
/// substitution.
inherited: Option<&'a CustomPropertiesMap>,
/// to resolve the environment to substitute `env()` variables.
device: &'a Device,
}
@ -831,18 +841,26 @@ fn substitute_all(custom_properties_map: &mut CustomPropertiesMap, device: &Devi
return None;
}
// Now we have shown that this variable is not in a loop, and
// all of its dependencies should have been resolved. We can
// start substitution now.
// Now we have shown that this variable is not in a loop, and all of its
// dependencies should have been resolved. We can start substitution
// now.
let result = substitute_references_in_value(&value, &context.map, &context.device);
match result {
Ok(computed_value) => {
context.map.insert(name, Arc::new(computed_value));
},
}
Err(..) => {
context.map.remove(&name);
},
// This is invalid, reset it to the unset (inherited) value.
let inherited = context.inherited.and_then(|m| m.get(&name)).cloned();
match inherited {
Some(computed_value) => {
context.map.insert(name, computed_value);
},
None => {
context.map.remove(&name);
},
};
}
}
// All resolved, so return the signal value.
@ -859,6 +877,7 @@ fn substitute_all(custom_properties_map: &mut CustomPropertiesMap, device: &Devi
stack: SmallVec::new(),
var_info: SmallVec::new(),
map: custom_properties_map,
inherited,
device,
};
traverse(name, &mut context);