UnigramDev/Unigram/dwrite-collection-key • c1bf81a • 2 files, +40/-11
Give the DWrite custom font collection a valid key

CreateCustomFontCollection takes the key size in bytes, but it was given
path1.size() + path2.size(), the summed character length of the two package
paths (~240) — while the key itself is a two-element array of pointers, 16
bytes. DWrite copied ~240 bytes out of a 16-byte stack array on every
PlaceholderImageHelper construction, so the key it stored was partly unrelated
stack memory, and how much varied with the install path length.

The key also pointed at two locals that die when the function returns, so the
pointers DWrite kept were dangling by the time it could hand them back to
CreateEnumeratorFromKey. The paths and the pointer array now live inside the
CustomFontLoader, which stays alive as long as it is registered, and the size
passed is sizeof that array. CustomFontFileEnumerator honours collectionKeySize
instead of assuming two entries.

Close() now unregisters the loader it registered on the shared DWrite factory,
after releasing the collection built from it. The factory is process-wide, so
without this every window thread left a loader and a custom collection on it for
the rest of the session.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

#unigram