SECURITY UPDATE: Out-of-bounds write via invalid block switch in the decoder
debian/patches/CVE-2026-111497.patch: return
BROTLI_DECODER_ERROR_FORMAT_BLOCK_SWITCH from DecodeBlockTypeAndLength
and propagate it through the literal, command and distance block-switch
decoders in c/dec/decode.c, add the error code to
c/include/brotli/decode.h