541277 - "ASSERTION: character/glyph clump contains no glyphs!"

Status: RESOLVED FIXED

(Core :: Graphics, defect)

Description

[Jesse Ruderman]

Attachment: testcase (might hang Firefox)

###!!! ASSERTION: character/glyph clump contains no glyphs!: 'glyphStart < glyphEnd', file /Users/jruderman/mozilla-central/gfx/thebes/src/gfxCoreTextFonts.cpp, line 733

###!!! ASSERTION: character/glyph contains no characters!: 'charStart != charEnd', file /Users/jruderman/mozilla-central/gfx/thebes/src/gfxCoreTextFonts.cpp, line 734

This is either a recent regression in Gecko or a regression from the recent Snow Leopard security update.

Comment 1

[Jesse Ruderman]

Attachment: testcase 2

Comment 2

[Jonathan Kew [:jfkthame]]

Attachment: correct the core text char/glyph clump scanner to avoid assertion and possible hang

The problem was a result of a hack in the Core Text code, intended to work around an issue with direction override codes (because Core Text deletes the glyphs corresponding to direction overrides, it can look as though those characters have formed ligatures).

A better solution than an ad-hoc index adjustment for that issue is to include spaces to separate the overrides from the "real" text content, as we used to do in the ATSUI code as well.

Comment 3

[Jonathan Kew [:jfkthame]]

Pushed http://hg.mozilla.org/mozilla-central/rev/263b6541c83f
including the testcases here as crashtests