Feeding -1 to xdup() isn't an error.

1 files changed, 4 insertions, 2 deletions

diff --git a/lib/lib.c b/lib/lib.c
index 7af2af11..ec491063 100644
--- a/lib/lib.c
+++ b/lib/lib.c
@@ -210,8 +210,10 @@ void xclose(int fd)
 
 int xdup(int fd)
 {
-	fd = dup(fd);
-	if (fd == -1) perror_exit("xdup");
+	if (fd != -1) {
+		fd = dup(fd);
+		if (fd == -1) perror_exit("xdup");
+	}
 	return fd;
 }