Don't treat TMUX_TMPDIR as a potential file

The point of setting TMUX_TMPDIR is to then make any labels from -L go to
that directory.  In the case of makesocketpath() with no TMUX_TMPDIR set,
would set both the path and the default socket to a file.  The checking of
the permissions on the file worked fine in that case, but when TMUX_TMPDIR
is set, won't work on a directory.

This fixes the problem by ensuring the check on the permissions is performed
on directories only.

1 files changed, 4 insertions, 2 deletions

diff --git a/tmux.c b/tmux.c
index 606c574f..9c81cff5 100644
--- a/tmux.c
+++ b/tmux.c
@@ -184,7 +184,8 @@ makesocketpath(const char *label)
 		errno = ENOTDIR;
 		return (NULL);
 	}
-	if (sb.st_uid != uid || (sb.st_mode & (S_IRWXG|S_IRWXO)) != 0) {
+	if (sb.st_uid != uid || (!S_ISDIR(sb.st_mode) &&
+		sb.st_mode & (S_IRWXG|S_IRWXO)) != 0) {
 		errno = EACCES;
 		return (NULL);
 	}
@@ -387,7 +388,8 @@ main(int argc, char **argv)
 		/* -L or default set. */
 		if (label != NULL) {
 			if ((path = makesocketpath(label)) == NULL) {
-				fprintf(stderr, "can't create socket\n");
+				fprintf(stderr, "can't create socket: %s\n",
+					strerror(errno));
 				exit(1);
 			}
 		}