Ignore default-shell (and use /bin/sh) if it invalid not just if it is

tmux itself, also refuse to set the option to something invalid in the
first place. GitHub issue 2120.

1 files changed, 3 insertions, 1 deletions

diff --git a/server-client.c b/server-client.c
index 02113386..f3a2b044 100644
--- a/server-client.c
+++ b/server-client.c
@@ -400,6 +400,8 @@ server_client_exec(struct client *c, const char *cmd)
 		shell = options_get_string(s->options, "default-shell");
 	else
 		shell = options_get_string(global_s_options, "default-shell");
+	if (!checkshell(shell))
+		shell = _PATH_BSHELL;
 	shellsize = strlen(shell) + 1;
 
 	msg = xmalloc(cmdsize + shellsize);
@@ -2009,7 +2011,7 @@ server_client_dispatch_shell(struct client *c)
 	const char	*shell;
 
 	shell = options_get_string(global_s_options, "default-shell");
-	if (*shell == '\0' || areshell(shell))
+	if (!checkshell(shell))
 		shell = _PATH_BSHELL;
 	proc_send(c->peer, MSG_SHELL, -1, shell, strlen(shell) + 1);