Bug 2389100

See: U+FE0E (text-style selector) ignored when COLRv1 emoji fonts are present

When a COLRv1 emoji font (e.g., Noto-COLRv1.ttf) is installed, the Unicode variation selector U+FE0E (text-style) is ignored, and emoji are always rendered in color. This breaks expected behavior, as U+FE0E should force monochrome rendering.

Steps to reproduce:

On a system with Noto-COLRv1.ttf (e.g., Fedora Rawhide), run:

pango-view --font="sans" test.txt

with the test.txt attached here: test.txt (this file contains: 🚀 🚀︎ (U+1F680 U+1F680 U+FE0E))

Expected output shown by pango-view: One colored rocket, one monochrome rocket. Actual output: two colored rockets.

If one tries the same on Fedora 42 with default fonts installed, i.e. no font with a COLR table, it works as expected. /usr/share/fonts/google-noto-color-emoji-fonts/Noto-COLRv1.ttf does not have U+FE0E according to fontconfig:

mfabian@f42:~
$ fc-list :charset=1f680,fe0e
/usr/share/fonts/gdouros-symbola/Symbola.ttf: Symbola:style=Regular
/usr/share/fonts/google-noto-emoji-fonts/NotoEmoji-Regular.ttf: Noto Emoji:style=Regular
mfabian@f42:~
$ fc-list :charset=1f680
/usr/share/fonts/twemoji/Twemoji.ttf: Twemoji:style=Regular
/usr/share/fonts/google-noto-color-emoji-fonts/NotoColorEmoji.ttf: Noto Color Emoji:style=Regular
/usr/share/fonts/hfg-gmuend-openmoji-black-fonts/OpenMoji-black-glyf.ttf: OpenMoji Black,OpenMoji Black:style=Regular,Regular
/usr/share/fonts/gdouros-symbola/Symbola.ttf: Symbola:style=Regular
/usr/share/fonts/google-noto-emoji-fonts/NotoEmoji-Regular.ttf: Noto Emoji:style=Regular
/usr/share/fonts/hfg-gmuend-openmoji-color-fonts/OpenMoji-color-glyf_colr_1.ttf: OpenMoji Color,OpenMoji Color:style=Regular,
Regular
mfabian@f42:~
$ 

and it is not used to render U+1F680 U+FE0E, instead /usr/share/fonts/google-noto-emoji-fonts/NotoEmoji-Regular.ttf is used which has both U+1F680 and U+FE0E.

Reproducible: Always