From 6e2bb7acf42589fb7130b039d0623e2ca42503dd Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Thu, 4 Sep 2014 22:21:17 -0400 Subject: fix multiple stdio functions' behavior on zero-length operations previously, fgets, fputs, fread, and fwrite completely omitted locking and access to the FILE object when their arguments yielded a zero length read or write operation independent of the FILE state. this optimization was invalid; it wrongly skipped marking the stream as byte-oriented (a C conformance bug) and exposed observably missing synchronization (a POSIX conformance bug) where one of these functions could wrongly complete despite another thread provably holding the lock. --- src/stdio/fputs.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'src/stdio/fputs.c') diff --git a/src/stdio/fputs.c b/src/stdio/fputs.c index 1112b192..4737f448 100644 --- a/src/stdio/fputs.c +++ b/src/stdio/fputs.c @@ -3,9 +3,7 @@ int fputs(const char *restrict s, FILE *restrict f) { - size_t l = strlen(s); - if (!l) return 0; - return (int)fwrite(s, l, 1, f) - 1; + return (int)fwrite(s, strlen(s), 1, f) - 1; } weak_alias(fputs, fputs_unlocked); -- cgit 1.4.1