[ft-devel] FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH by default?

[Behdad Esfahbod]

Hi,

Every user of FreeType that I know has once in their lifetime hit the bug that
with many common CJK fonts, non-CJK characters take doublewidth where they
should take a single one.  The fix always has been to pass
FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH to FreeType, as the fonts have the bit set
wrongly.  A "monospace" CJK font is never monospace.  It has single-width
glyphs, and double-width, hence setting global-advance is wrong in the font.

But since this is such a common issue, I wonder if FreeType should simply
ignore global advance by default.  Cairo and fontconfig always pass that flag
to FreeType.  I've seen this bug hit Qt before.  And most recently I watched
it hit Skia.

What do you think?

behdad