If you think a bug might affect users in the 57 release, please set the correct tracking and status flags for Release Management.

[harfbuzz] overlapping glyphs with diacritics in monospaced fonts

RESOLVED FIXED

Status

()

Core
Graphics
RESOLVED FIXED
7 years ago
7 years ago

People

(Reporter: jfkthame, Assigned: jfkthame)

Tracking

unspecified
x86
Windows 7
Points:
---

Firefox Tracking Flags

(blocking2.0 final+)

Details

Attachments

(2 attachments)

(Assignee)

Description

7 years ago
(Also posted to harfbuzz mailing list.)

Monospaced fonts such as DejaVu Sans Mono and Consolas (Win7) render incorrectly when combining diacritics are used; the following glyph overprints the base+diacritic combination. This causes the wordwrap-03 reftest to fail under harfbuzz on Win7.

Simple testcase:
data:text/html,<div style="font-family:consolas,monospace">foobar<br/>fo&#xf3;bar<br/>foo&#x301;bar

On Win7 with gfx.font_rendering.harfbuzz.level=1, the third line will show the problem.
(Assignee)

Comment 1

7 years ago
Created attachment 468367 [details]
screenshot showing overlapping glyphs from the testcase
Assignee: nobody → jfkthame
(Assignee)

Comment 2

7 years ago
Created attachment 468373 [details] [diff] [review]
patch, v1 - don't override advances in mark-to-base attachment

(As posted to the harfbuzz mailing list.)
Attachment #468373 - Flags: review?(jdaggett)
(Assignee)

Comment 3

7 years ago
Requesting blocking-2.0 as this prevents us enabling harfbuzz by default on windows, due to reftest failures.
blocking2.0: --- → ?
blocking2.0: ? → final+

Comment 4

7 years ago
Comment on attachment 468373 [details] [diff] [review]
patch, v1 - don't override advances in mark-to-base attachment

Looks good.  Probably want a reftest for this.
Attachment #468373 - Flags: review?(jdaggett) → review+
(Assignee)

Comment 5

7 years ago
http://hg.mozilla.org/mozilla-central/rev/459aab9180b9

The wordwrap-03 reftest already catches this on Windows when we enable harfbuzz, as it uses combining diacritics in monospace. The first patch in bug 590101 will cause it to catch this issue on OS X as well, because it will hit the harfbuzz text path instead of coretext there as well. So we're sufficiently covered, I think.
Status: NEW → RESOLVED
Last Resolved: 7 years ago
Resolution: --- → FIXED
You need to log in before you can comment on or make changes to this bug.