Bug 1406222 - servo: Don't assume that inputs to compute_style_with_inputs have any rules. r=heycam, a=ritu
It could be a text style, which never has any rules attached to it.
Source-Repo:
https://github.com/servo/servo
Source-Revision:
117dbfaac20d8a388cf3cf5d2bc103b9d6249ee8
--- a/servo/components/style/stylist.rs
+++ b/servo/components/style/stylist.rs
@@ -891,22 +891,22 @@ impl Stylist {
parent_style_ignoring_first_line: &ComputedValues,
layout_parent_style: &ComputedValues,
font_metrics: &FontMetricsProvider,
cascade_flags: CascadeFlags
) -> Arc<ComputedValues> {
// We need to compute visited values if we have visited rules or if our
// parent has visited values.
let visited_values = if inputs.visited_rules.is_some() || parent_style.get_visited_style().is_some() {
- // Slightly annoying: we know that inputs has either rules or
- // visited rules, but we can't do inputs.rules() up front because
- // maybe it just has visited rules, so can't unwrap_or.
+ // At this point inputs may have visited rules, or rules, or both,
+ // or neither (e.g. if it's a text style it may have neither). So
+ // we have to be a bit careful here.
let rule_node = match inputs.visited_rules.as_ref() {
Some(rules) => rules,
- None => inputs.rules.as_ref().unwrap(),
+ None => inputs.rules.as_ref().unwrap_or(self.rule_tree().root()),
};
let inherited_style;
let inherited_style_ignoring_first_line;
let layout_parent_style_for_visited;
if cascade_flags.contains(IS_LINK) {
// We just want to use our parent style as our parent.
inherited_style = parent_style;
inherited_style_ignoring_first_line = parent_style_ignoring_first_line;