0.47.3: color/bitmap emoji rendered far too small (fontconfig size matrix double-applied)

After updating to 0.47.3, all color emoji render shrunk to a tiny dot in the top-left of their cell. It happens everywhere color emoji appear (shell prompt, neovim, plain `printf`), not just one app. This is the same visual symptom as #10123 (closed with "use symbol_map"), but I think that workaround misses the actual cause, which is a fontconfig size matrix being applied twice. Details below. ### Repro ```sh kitty --config NONE sh -c 'printf "\U0001F40D snake\n"; sleep 5' ``` The snake shows as a dot instead of a full-cell emoji. ### Bisect 0.47.2 renders it correctly, 0.47.3 does not. The only font/glyph change in `v0.47.2..v0.47.3` is [ee937bdd1b](https://github.com/kovidgoyal/kitty/commit/ee937bdd1b86a23df4bc1698f01128ea979b753c) ("freetype: route FC_MATRIX through cairo for color glyphs"). Reverting just that commit on top of 0.47.3 restores correct rendering. ### Root cause Noto Color Emoji is a fixed-size CBDT bitmap font, so fontconfig hands every consumer a downscale matrix to fit it to the requested pixel size. On this system: ``` $ fc-match -v 'Noto Color Emoji' | grep matrix matrix: [0.114679 0; 0 0.114679](w) ``` kitty already does its own cell-fit scaling for color glyphs (`fit_cairo_glyph`). Before `ee937bdd1b` it ignored the fontconfig matrix for these. Now `apply_cairo_font_size` feeds that `~0.1147x` matrix into the cairo font matrix as well, so the already-cell-sized emoji gets scaled down by another ~9x. Font selection is correct, only the scale is wrong: ``` $ kitty --debug-font-fallback sh -c 'printf "\U0001F40D\n"' U+1f40d emoji_presentation Face(family=Noto Color Emoji ... color=True) ``` So the matrix path in `apply_cairo_font_size` probably needs to be skipped for fixed-size / color-bitmap faces, where the size is already handled by `fit_cairo_glyph` rather than the font matrix. ### Environment ``` kitty 0.47.3 Linux 7.0.12-xanmod1 x86_64, Wayland (niri) Noto Color Emoji 2.051 (CBDT bitmap) freetype 2.14.2, fontconfig 2.17.1, cairo 1.18.4 ```