musl - musl - an implementation of the standard library for Linux-based systems

diff --git a/src/stdio/fileno.c b/src/stdio/fileno.c
index ba7f9391..0bd0e988 100644
--- a/src/stdio/fileno.c
+++ b/src/stdio/fileno.c

@@ -1,13 +1,16 @@

#include "stdio_impl.h"

+#include <errno.h>

int fileno(FILE *f)

{

- /* f->fd never changes, but the lock must be obtained and released

- * anyway since this function cannot return while another thread

- * holds the lock. */

FLOCK(f);

+ int fd = f->fd;

FUNLOCK(f);

- return f->fd;

+ if (fd < 0) {

+ errno = EBADF;

+ return -1;

+ }

+ return fd;

}

weak_alias(fileno, fileno_unlocked);