autohinter: Don't change digit widths if all widths are the same.
This fixes FreeDesktop bug #21197.
* src/autofit/afglobal.c (AF_DIGIT): New macro.
(af_face_globals_compute_script_coverage): Mark ASCII digits in
`glyph_scripts' array.
(af_face_globals_get_metrics): Updated.
(af_face_globals_is_digit): New function.
* src/autofit/afglobal.h: Updated.
(AF_ScriptMetricsRec): Add `digits_have_same_width' flag.
* src/autofit/aflatin.c: Include FT_ADVANCES_H.
(af_latin_metrics_check_digits): New function.
(af_latin_metrics_init): Use it.
* src/autofit/aflatin.h: Updated.
* src/autofit/afcjk.c (af_cjk_metrics_init): Updated.
* src/autofit/aflatin2.c: Similar changes as with aflatin.c.
* src/autofit/afloader.c (af_loader_load_g): Test digit width.
* docs/CHANGES: Document it.
10 files changed