===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/tmux/server-client.c,v
retrieving revision 1.393
retrieving revision 1.394
diff -u -r1.393 -r1.394
--- src/usr.bin/tmux/server-client.c	2022/03/24 09:05:57	1.393
+++ src/usr.bin/tmux/server-client.c	2022/05/30 12:48:57	1.394
@@ -1,4 +1,4 @@
-/* $OpenBSD: server-client.c,v 1.393 2022/03/24 09:05:57 nicm Exp $ */
+/* $OpenBSD: server-client.c,v 1.394 2022/05/30 12:48:57 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -2775,6 +2775,14 @@
 	}
 }
 
+/* Callback when command is not allowed. */
+static enum cmd_retval
+server_client_read_only(struct cmdq_item *item, __unused void *data)
+{
+	cmdq_error(item, "client is read-only");
+	return (CMD_RETURN_ERROR);
+}
+
 /* Callback when command is done. */
 static enum cmd_retval
 server_client_command_done(struct cmdq_item *item, __unused void *data)
@@ -2799,6 +2807,7 @@
 	char			**argv, *cause;
 	struct cmd_parse_result	 *pr;
 	struct args_value	 *values;
+	struct cmdq_item	 *new_item;
 
 	if (c->flags & CLIENT_EXIT)
 		return;
@@ -2837,7 +2846,12 @@
 	free(values);
 	cmd_free_argv(argc, argv);
 
-	cmdq_append(c, cmdq_get_command(pr->cmdlist, NULL));
+	if ((c->flags & CLIENT_READONLY) &&
+	    !cmd_list_all_have(pr->cmdlist, CMD_READONLY))
+		new_item = cmdq_get_callback(server_client_read_only, NULL);
+	else
+		new_item = cmdq_get_command(pr->cmdlist, NULL);
+	cmdq_append(c, new_item);
 	cmdq_append(c, cmdq_get_callback(server_client_command_done, NULL));
 
 	cmd_list_free(pr->cmdlist);
@@ -3071,9 +3085,11 @@
 			continue;
 
 		log_debug("client %s set flag %s", c->name, next);
-		if (not)
+		if (not) {
+			if (c->flags & CLIENT_READONLY)
+				flag &= ~CLIENT_READONLY;
 			c->flags &= ~flag;
-		else
+		} else
 			c->flags |= flag;
 		if (flag == CLIENT_CONTROL_NOOUTPUT)
 			control_reset_offsets(c);