Use unlocked POSIX EOF/error queries after unlocked byte operations so status synchronization cannot reacquire the stream lock. Keep the verified UCRT status calls on Windows, and cover byte, status, error, and held-lock behavior.
Co-authored-by: MarcZX100 <marczxrr@gmail.com>
FreeBSD's __sflags reads the access character, then b, +, x, e and v, and
stops at the first other character without failing, so "rt" opens for
reading. On Windows fopen inserted b after the first character and passed
the rest on, so "rt" became "rbt", the CRT rejected it with EINVAL, and
fopen threw. vkQuake opens history.txt with "rt" at startup. freopen
accepted only a fixed list of modes.
Both now parse the mode like __sflags. An unknown access character, or x
on a read-only stream, returns NULL with EINVAL; x on an existing file
returns NULL with EEXIST; e and v are accepted and ignored.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
FreeBSD's setvbuf takes a zero size with _IOFBF or _IOLBF as "pick the
buffer size". The UCRT rejects sizes below 2 for those modes through
its invalid parameter handler, so the call failed on Windows and a test
process was terminated. A zero size now drops the given buffer and
asks the host for one of BUFSIZ bytes.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Romans Pokrovskis
MarcZX100
Adrià Franch
Hannah Lyons
Scott Schuster
LeandroLP23
Dean
Ethan Barr
Nicolas Abosch
asimplestray
SamG-Coder