Reject $SHELL if it is not a full path.

1 files changed, 3 insertions, 1 deletions

diff --git a/tmux.c b/tmux.c
index 196edf6c..5d4fda72 100644
--- a/tmux.c
+++ b/tmux.c
@@ -98,7 +98,9 @@ getshell(void)
 int
 checkshell(const char *shell)
 {
-	if (shell == NULL || *shell == '\0' || areshell(shell))
+	if (shell == NULL || *shell == '\0' || *shell != '/')
+		return (0);
+	if (areshell(shell))
 		return (0);
 	if (access(shell, X_OK) != 0)
 		return (0);