layout: Count word separators as justification opportunities when trimming whitespace (#31161)

Before counting whitepsace-only `GlyphStore`s where counted as a single
justification opportunity when trimming whitespace from the front and
back of lines. This isn't correct, instead count the actual number of
word seperators of the trimmed `GlyphStore`s.

These two counts can be different in the case where whitespace collapse
isn't happening yet (flexbox). In addition, using word seperators means
the code is making less assumptions about the contents of the line and
is more robust.

This fixes some crashes in flexbox tests on debug builds.

Co-authored-by: Rakhi Sharma <atbrakhi@igalia.com>
This commit is contained in:
Martin Robinson 2024-01-23 12:47:13 +01:00 committed by GitHub
parent 1d67aa44ca
commit 7de0486e2e
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
3 changed files with 25 additions and 19 deletions

View file

@ -179,13 +179,14 @@ impl LineUnderConstruction {
// > as well as any trailing U+1680 OGHAM SPACE MARK whose white-space
// > property is normal, nowrap, or pre-line.
let mut whitespace_trimmed = Length::zero();
let mut spaces_trimmed = 0;
let mut word_seperators_trimmed = 0;
for item in self.line_items.iter_mut().rev() {
if !item.trim_whitespace_at_end(&mut whitespace_trimmed, &mut spaces_trimmed) {
if !item.trim_whitespace_at_end(&mut whitespace_trimmed, &mut word_seperators_trimmed) {
break;
}
}
self.justification_opportunities -= spaces_trimmed;
self.justification_opportunities -= word_seperators_trimmed;
whitespace_trimmed
}
}
@ -399,14 +400,15 @@ impl UnbreakableSegmentUnderConstruction {
/// This prevents whitespace from being added to the beginning of a line.
fn trim_leading_whitespace(&mut self) {
let mut whitespace_trimmed = Length::zero();
let mut spaces_trimmed = 0;
let mut word_seperators_trimmed = 0;
for item in self.line_items.iter_mut() {
if !item.trim_whitespace_at_start(&mut whitespace_trimmed, &mut spaces_trimmed) {
if !item.trim_whitespace_at_start(&mut whitespace_trimmed, &mut word_seperators_trimmed)
{
break;
}
}
self.inline_size -= whitespace_trimmed;
self.justification_opportunities -= spaces_trimmed;
self.justification_opportunities -= word_seperators_trimmed;
}
/// Prepare this segment for placement on a new and empty line. This happens when the