VTE: Fix crash when "send_cmd_prefix" is NULL

src/vte.c

@@ -802,7 +802,7 @@ static GtkWidget *vte_create_popup_menu(void)
  * on the prompt). */
 gboolean vte_send_cmd(const gchar *cmd)
 {
-	if (clean)
+	if (clean && cmd)
 	{
 		vf->vte_terminal_feed_child(VTE_TERMINAL(vc->vte), cmd, strlen(cmd));
 		set_clean(TRUE); /* vte_terminal_feed_child() also marks the vte as not clean */
@@ -875,7 +875,8 @@ void vte_cwd(const gchar *filename, gboolean force)
 		{
 			/* use g_shell_quote to avoid problems with spaces, '!' or something else in path */
 			gchar *quoted_path = g_shell_quote(path);
-			gchar *cmd = g_strconcat(vc->send_cmd_prefix, "cd ", quoted_path, "\n", NULL);
+			const gchar *cmd_prefix = vc->send_cmd_prefix ? vc->send_cmd_prefix : "";
+			gchar *cmd = g_strconcat(cmd_prefix, "cd ", quoted_path, "\n", NULL);
 			if (! vte_send_cmd(cmd))
 			{
 				const gchar *msg = _("Directory not changed because the terminal may contain some input (press Ctrl+C or Enter to clear it).");