Don't error if renaming a session to its current name, from shik dot

chen at gmail dot com.

cmd-rename-session.c

@@ -19,6 +19,7 @@
 #include <sys/types.h>
 
 #include <stdlib.h>
+#include <string.h>
 
 #include "tmux.h"
 
@@ -50,6 +51,9 @@ cmd_rename_session_exec(struct cmd *self, struct cmdq_item *item)
 	const char	*newname;
 
 	newname = args->argv[0];
+	if (strcmp(newname, s->name) == 0)
+		return (CMD_RETURN_NORMAL);
+
 	if (!session_check_name(newname)) {
 		cmdq_error(item, "bad session name: %s", newname);
 		return (CMD_RETURN_ERROR);