ttfremap does not work to encode a SMP character

[devosb]

I used ttfremap to encode an alternate glyph as a character. If the codepoint is in the SMP, then the resulting font is not correct. Specially, the new font

• has an extra cmap added (platform 0, encoding 0 (which is deprecated), format 12
• the new character does not have the correct glyph, it has a rectangle which looks like it was copied from the .notdef glyph. This is the case in all three format 12 cmaps.

The command line I used was

ttfremap -r -c iru_remap.txt ThiruValluvar-Regular.ttf ThiruValluvarIRU-Regular.ttf

where the file iru_remap.txt contained

n, nukta.ringdbl, 1133B

Test fonts can be found on a CI.

[devosb]

I needed to use the glyphname in the TTF, not the UFO sources. So the file iru_remap.txt should have contained

n, u1133C.ringdbl, 1133C

With this fix the desired glyph appears. However, the extra cmap (0, 0, 12) is still added.