Closed Bug 1408366 Opened 2 years ago Closed 2 years ago

U+034F COMBINING GRAPHEME JOINER breaks shaping in some fonts

Categories

(Core :: Layout: Text and Fonts, enhancement)

52 Branch
enhancement
Not set

Tracking

()

RESOLVED FIXED
mozilla58
Tracking Status
firefox58 --- fixed

People

(Reporter: dr.khaled.hosny, Assigned: jfkthame)

References

Details

Attachments

(3 files)

It seems that if a font lacks a glyph for U+034F COMBINING GRAPHEME JOINER, Firefox will fallback to a different font and break shaping, but this fallback is unnecessary since HarfBuzz will deal with it just fine.

Test case:
data:text/html;charset=utf8,<p style="font: 100pt Amiri">ىٕ͏ِد</p>

The fonts tab in the developer tools shows that Amiri and another font are used.
Makes sense; we already deal with certain other control characters in this way, allowing them in the run regardless of whether the font explicitly supports them. We should just treat CGJ the same.
Assignee: nobody → jfkthame
Status: NEW → ASSIGNED
Attachment #8918301 - Flags: review?(jmuizelaar) → review+
Pushed by jkew@mozilla.com:
https://hg.mozilla.org/integration/mozilla-inbound/rev/b6f55f929971
Unicode combining grapheme joiner (U+034F) should not break the font run. r=jrmuizel
https://hg.mozilla.org/mozilla-central/rev/b6f55f929971
Status: ASSIGNED → RESOLVED
Closed: 2 years ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla58
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