Closed Bug 1230497 Opened 4 years ago Closed 4 years ago

Core Text shaping failure in Indic text due to join-control characters

Categories

(Core :: Graphics: Text, defect)

Unspecified
macOS
defect
Not set

Tracking

()

RESOLVED FIXED
mozilla45
Tracking Status
firefox45 --- fixed

People

(Reporter: jfkthame, Assigned: jfkthame)

Details

Attachments

(1 file)

Spun off from bug 1194105 comment 6, as I think this is distinct from the original issue in that bug.

Testcase:

  data:text/html;charset=utf-8,
    <span style="font:36px Telugu MN">&%23xc15;&%23xc4d;&%23x200c;

should render the same as:

  data:text/html;charset=utf-8,
    <span style="font:36px Telugu MN">&%23xc15;&%23xc4d;

i.e. the ZWNJ should not affect it. But it fails, because Telugu MN doesn't include glyphs for ZWNJ/ZWJ, and this causes Core Text to use a fallback (even though it won't be visible). This then makes us think shaping failed, and punt to harfbuzz, which can't actually shape this (AAT-only) font properly.
Assignee: nobody → jfkthame
Status: NEW → ASSIGNED
Attachment #8695817 - Flags: review?(jdaggett) → review+
https://hg.mozilla.org/integration/mozilla-inbound/rev/803db6db0f680e066a2e3830cdd22959b07a0459
Bug 1230497 - Ignore font fallback in Core Text shaping if it's just for a join-control character. r=jdaggett
https://hg.mozilla.org/mozilla-central/rev/803db6db0f68
Status: ASSIGNED → RESOLVED
Closed: 4 years ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla45
You need to log in before you can comment on or make changes to this bug.