From b488b321ed37e4d5f04e99aacb647899a897e985 Mon Sep 17 00:00:00 2001 From: Boris Zbarsky Date: Thu, 5 Oct 2017 23:16:14 -0400 Subject: [PATCH] Don't assume that inputs to compute_style_with_inputs have any rules. It could be a text style, which never has any rules attached to it. Fixes https://bugzilla.mozilla.org/show_bug.cgi?id=1406222 --- components/style/stylist.rs | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/components/style/stylist.rs b/components/style/stylist.rs index b992b7c248f..a8bc12085c1 100644 --- a/components/style/stylist.rs +++ b/components/style/stylist.rs @@ -894,12 +894,12 @@ impl Stylist { // 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.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;