The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=6e13794fbe6e82c21365d0fd66769bf8b19c0197
commit 6e13794fbe6e82c21365d0fd66769bf8b19c0197 Author: Mark Johnston <[email protected]> AuthorDate: 2022-03-25 14:46:24 +0000 Commit: Mark Johnston <[email protected]> CommitDate: 2022-03-28 15:23:46 +0000 libc: Restore fp state upon flush error in fputc This is akin to commit bafaa70b6f9098d83d074968c8e6747ecec1e118. Reported by: Guy Yur <[email protected]> Fixes: 86a16ada1ea6 MFC after: 3 days Sponsored by: The FreeBSD Foundation --- lib/libc/stdio/wbuf.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/lib/libc/stdio/wbuf.c b/lib/libc/stdio/wbuf.c index e1aa70243e94..6cd75145a271 100644 --- a/lib/libc/stdio/wbuf.c +++ b/lib/libc/stdio/wbuf.c @@ -52,6 +52,7 @@ __FBSDID("$FreeBSD$"); int __swbuf(int c, FILE *fp) { + unsigned char *old_p; int n; /* @@ -87,8 +88,15 @@ __swbuf(int c, FILE *fp) } fp->_w--; *fp->_p++ = c; - if (++n == fp->_bf._size || (fp->_flags & __SLBF && c == '\n')) - if (__fflush(fp)) + old_p = fp->_p; + if (++n == fp->_bf._size || (fp->_flags & __SLBF && c == '\n')) { + if (__fflush(fp)) { + if (fp->_p == old_p) { + fp->_p--; + fp->_w++; + } return (EOF); + } + } return (c); }
