Claude 312dee594b Encode U+FFFF as three bytes instead of an overlong four ...

The \uXXXX decoder tested `ch < 0xFFFF` before taking the three-byte UTF-8
path, so U+FFFF itself fell through to the four-byte branch and came out as
F0 8F BF BF -- an overlong, and therefore invalid, encoding of a code point
that fits in three bytes.

check_utf8() only checks that continuation bytes look like continuation
bytes, not that a sequence is the shortest form, so nothing downstream
noticed: a GeoJSON attribute containing U+FFFF put invalid UTF-8 into the
output tile, where a strict consumer would reject it.

Since `ch` is parsed from exactly four hex digits it cannot exceed 0xFFFF
on its own, so after this change the four-byte branch is reached only for a
code point assembled from a surrogate pair, which is the only way to name
one above the BMP.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017KNxyHKasyWrWcvre2yK4r

2026-08-12 18:35:44 +00:00

..

jsonpull.cpp

Encode U+FFFF as three bytes instead of an overlong four

2026-08-12 18:35:44 +00:00

jsonpull.h

Correct two stale comments in the jsonpull port

2026-08-12 18:16:37 +00:00