Bug 156841 - [GTK] "-webkit-line-box-contain: glyphs replaced" sets height of arabic glyphs to zero
Summary: [GTK] "-webkit-line-box-contain: glyphs replaced" sets height of arabic glyph...
Status: NEW
Alias: None
Product: WebKit
Classification: Unclassified
Component: Text (show other bugs)
Version: WebKit Nightly Build
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Nobody
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2016-04-21 02:59 PDT by Frédéric Wang (:fredw)
Modified: 2017-03-11 11:04 PST (History)
3 users (show)

See Also:

Attachments
testcase (538 bytes, text/html)
2016-04-21 02:59 PDT, Frédéric Wang (:fredw) 		no flags Details
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Description Frédéric Wang (:fredw) 2016-04-21 02:59:15 PDT 
Created attachment 276904 [details]
testcase

This was discussed in bug 153208. In the attached testcase:

1) green background is used for arabic and latin text.
2) red background is used for arabic and latin text, using "-webkit-line-box-contain: glyphs replaced"
3) blue background is used for arabic and latin text in a MathML <mi> element (which currently uses "-webkit-line-box-contain: glyphs replaced", see bug 151592)

This works correctly for latin, but the background of Arabic text does not appear because the height of the calculated bounding box is incorrect. After bug 153208, MathML uses this exact bounding box for the layout and so Arabic text no longer appears.

I was able to reproduce this problem on GTK but this works correctly on Mac, so I guess it is specific to the Linux graphics backend.