Tingzhong Luo (@tzluo) commented about dlls/dwrite/tests/font.c:
+ hr = IDWriteBitmapRenderTarget_DrawGlyphRun(target, 0.0f, 0.0f, DWRITE_MEASURING_MODE_GDI_NATURAL, + &run, params, RGB(255, 0, 0), &box); + ok(hr == S_OK, "Failed to draw a run, hr %#lx.\n", hr); + ok(!IsRectEmpty(&box), "got empty rect\n"); + + /* Check glyph position */ + IDWriteFontFace_Release(fontface); + fontface = create_rectfallback_fontface(factory); + + /* 'A' map to a full black rectangle */ + ch = 'A'; + glyphs[0] = 0; + hr = IDWriteFontFace_GetGlyphIndices(fontface, &ch, 1, glyphs); + ok(hr == S_OK, "Unexpected hr %#lx.\n", hr); + ok(glyphs[0] > 0, "got %u\n", glyphs[0]); + glyphs[1] = glyphs[0]; A new font has been created via FontForge for this test.
-- https://gitlab.winehq.org/wine/wine/-/merge_requests/3718#note_44291