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crash on using mutator to instantiate from a VF

See original GitHub issue

Hi. I am using a script @chrissimpkins wrote to instantiate statics from a VF. It looks like mutator/ttLib is crashing on the gvar table.

Traceback (most recent call last):
  File "/Users/stupakm/Documents/freelance/code_apps_etc/vf2s.py", line 170, in <module>
    main()
  File "/Users/stupakm/Documents/freelance/code_apps_etc/vf2s.py", line 118, in main
    instantiateVariableFont(font, instance_location, inplace=True)
  File "/Users/stupakm/venvs/type-tools-py3/lib/python3.7/site-packages/fontTools/varLib/mutator.py", line 178, in instantiateVariableFont
    gvar = varfont['gvar']
  File "/Users/stupakm/venvs/type-tools-py3/lib/python3.7/site-packages/fontTools/ttLib/ttFont.py", line 392, in __getitem__
    table.decompile(data, self)
  File "/Users/stupakm/venvs/type-tools-py3/lib/python3.7/site-packages/fontTools/ttLib/tables/_g_v_a_r.py", line 111, in decompile
    numPointsInGlyph, sharedCoords, axisTags, gvarData)
  File "/Users/stupakm/venvs/type-tools-py3/lib/python3.7/site-packages/fontTools/ttLib/tables/_g_v_a_r.py", line 227, in decompileGlyph_
    sharedTuples, data, 4, offsetToData)
  File "/Users/stupakm/venvs/type-tools-py3/lib/python3.7/site-packages/fontTools/ttLib/tables/TupleVariation.py", line 553, in decompileTupleVariationStore
    tableTag, axisTags, tupleData, pointDeltaData))
  File "/Users/stupakm/venvs/type-tools-py3/lib/python3.7/site-packages/fontTools/ttLib/tables/TupleVariation.py", line 596, in decompileTupleVariation_
    len(points), tupleData, pos)
  File "/Users/stupakm/venvs/type-tools-py3/lib/python3.7/site-packages/fontTools/ttLib/tables/TupleVariation.py", line 414, in decompileDeltas_
    runHeader = byteord(data[pos])
IndexError: index out of range

The file I’m using here is the Italic in my Open Sans repo. (The Roman works fine.)

Issue Analytics

State:
Created 5 years ago
Comments:14 (6 by maintainers)

Top GitHub Comments

1reaction

benkielcommented, Apr 8, 2019

@laerm0 Oh man, if it stopped doing that I’d be so happy. I doubt I’m on the latest, I pick VTT up every couple months, so I’m not frequently using it. Thank you for the tip!

1reaction

anthrotypecommented, Apr 8, 2019

oh I misunderstood. In any case, whatever tool you’re using to post-process OpenSans as fontTools varLib originally built it, that may be modifying the glyph point indexes in the glyf table, will inevitably break gvar.