Overview of changes leading to 14.5.1
Thursday, October 1, 2026
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- Map the `fonupa` (Uralic Phonetic Alphabet) BCP 47 variant to the `UPPH`
  OpenType language system tag.
- Produce smaller `cmap` subtables and drop no-op variation device tables when
  subsetting.
- Fix possible deadlock in `hb_font_destroy()` after `hb_ft_font_set_funcs()`,
  a regression from 14.5.0.
- Fix signed integer overflows when scaling glyph extents and applying
  synthetic slant and emboldening.
- Fix float-to-int overflow in `VARC` component axis coordinates with
  malformed fonts.
- Fix a memory leak in the experimental WebAssembly shaper when shaping with
  features.
- Fix accumulator overflows in the experimental raster library when rendering
  glyphs with very many overlapping edges.
- Fix heap buffer overflow in the experimental GPU library with malicious
  `COLR` fonts.
- Various build and CI fixes.