377623 - Crash [@ GfxTextRun::ComputeLigatureData] with missing glyph and Gujarati vowel sign

Status: RESOLVED WORKSFORME

(Core :: Graphics, defect)

Description

[Simon Montagu :smontagu]

Attachment: testcase

###!!! ASSERTION: First character must be the start of a cluster and can't be a ligature continuation!: 'aCharIndex > 0 || (aGlyph.IsClusterStart() && !aGlyph.IsLigatureContinuation())', file ../../../dist/include/thebes/gfxFont.h, line 1019
###!!! ASSERTION: Ligature at the start of the run??: 'ligStart > 0', file /home/smontagu/mozwork/debugtree/mozilla/gfx/thebes/src/gfxFont.cpp, line 703
###!!! ASSERTION: Unknown character type!: 'glyphData->IsComplexCluster()', file /home/smontagu/mozwork/debugtree/mozilla/gfx/thebes/src/gfxFont.cpp, line 681

Followed by crash

Comment 1

[Simon Montagu :smontagu]

Top of stack:

#6  0xb6eef8d0 in gfxTextRun::ComputeClusterAdvance (this=0x8144168,
    aClusterOffset=4294967295)
    at /home/smontagu/mozwork/debugtree/mozilla/gfx/thebes/src/gfxFont.cpp:687
#7  0xb6eef9b7 in gfxTextRun::ComputeLigatureData (this=0x8144168,
    aPartOffset=0, aProvider=0x0)
    at /home/smontagu/mozwork/debugtree/mozilla/gfx/thebes/src/gfxFont.cpp:708
#8  0xb6eefdbf in gfxTextRun::ShrinkToLigatureBoundaries (this=0x8144168,
    aStart=0xbf9775a8, aEnd=0xbf9775a4)
    at /home/smontagu/mozwork/debugtree/mozilla/gfx/thebes/src/gfxFont.cpp:840
#9  0xb6ef274a in gfxTextRun::GetAdvanceWidth (this=0x8144168, aStart=0,
    aLength=2, aProvider=0xbf97761c)
    at /home/smontagu/mozwork/debugtree/mozilla/gfx/thebes/src/gfxFont.cpp:1339
#10 0xb6fb08ca in nsThebesFontMetrics::GetWidth (this=0x8a35aa8,
    aString=0xbf977ad0, aLength=2, aWidth=@0xbf977678, aFontID=0x0,
    aContext=0x81448c0)
    at /home/smontagu/mozwork/debugtree/mozilla/gfx/src/thebes/nsThebesFontMetrics.cpp:352

Comment 2

[Simon Montagu :smontagu]

Note that the first character, U+770, is a non-allocated codepoint in the Arabic Supplement range, so it defaults to RTL.

Comment 3

[Window Snyder]

If you are not the right person to assign this to, please help us find someone that is.

Comment 4

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Is this still an issue? It may have been fixed by Karl's rework of Pango glyph extraction.

Comment 5

[Simon Montagu :smontagu]

This is now fixed.