Closed Bug 1403166 Opened 3 years ago Closed 3 years ago
Khmer Unicode Renders Incorrectly using mac
OS system fonts
10.59 KB, image/png
5.16 KB, image/png
For Khmer AAT fonts, enable the Line Initial Smart Swashes feature, which is (incorrectly) required for some vowels to render properly
2.13 KB, patch
|Details | Diff | Splinter Review|
User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/604.1.38 (KHTML, like Gecko) Version/11.0 Safari/604.1.38 Steps to reproduce: Browse to a Khmer website (like https://plovpit.com ) Actual results: The title bar will not render Khmer correctly in Firefox on Mac OS Sierra Expected results: Khmer should render correctly as it does in Chrome and Safari
Component: Untriaged → Layout: Text
Product: Firefox → Core
Normally, for complex-script fonts on macOS, we route the shaping through Core Text so that Apple's AAT fonts will work properly. Unfortunately, this doesn't seem to be a good option for the Khmer fonts they're now shipping, which also have OpenType layout tables; we'll do better to allow harfbuzz to handle them.
Assignee: nobody → jfkthame
Status: UNCONFIRMED → ASSIGNED
Ever confirmed: true
Hmm, I wonder if this is actually another example like bug 1370927, where the AAT fonts require an "unexpected" feature to be enabled in order to shape correctly. I'll do a quick experiment to check that; if so, that would probably be the better workaround to apply.
Yep, this appears to fix the Khmer rendering, just like the Indic split-vowel cases. Sad, but at least it's simple.
Attachment #8917460 - Flags: review?(jmuizelaar)
Comment on attachment 8916637 [details] [diff] [review] Prefer HarfBuzz shaping over Core Text for the macOS Khmer fonts that include both AAT and OpenType Layout tables, as the latter seem to work better Obsoleting this patch; I think the fix in gfxCoreTextShaper is a better approach, as it means we're using the same rendering path for these fonts as Apple does in their own software.
Attachment #8917460 - Flags: review?(jmuizelaar) → review+
Pushed by firstname.lastname@example.org: https://hg.mozilla.org/integration/mozilla-inbound/rev/060b6a8b02f6 For Khmer AAT fonts, enable the Line Initial Smart Swashes feature, which is (incorrectly) required for some vowels to render properly. r=jrmuizel
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