cli: fix nft -i command crashes when try to input multi line command

When try to input multiline command in "nft -i", it crashes.

Issue is, function cli_append_multiline() return null in case of
multiline command. But in the calling function cli_complete(),
cli_exit is getting called, which in turn calls
rl_callback_handler_remove() and the handler is getting removed.

 [root@localhost ~]# nft -i
 nft> add table filter
 nft> list table \

 readline: readline_callback_read_char() called with no handler!
 Aborted (core dumped)
 [root@localhost ~]#

After this patch, it shows:

 nft> list table \
 .... filter
 table ip filter {
 }
 nft>

The ".... " prompt is used to indicate a multiline command, similar to
what Python does.

Signed-off-by: Guruswamy Basavaiah <guru2018@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 6 insertions, 2 deletions

diff --git a/src/cli.c b/src/cli.c
index 8875207d..f748a0e2 100644
--- a/src/cli.c
+++ b/src/cli.c
@@ -66,6 +66,7 @@ static char *cli_append_multiline(char *line)
 		multiline = line;
 		rl_save_prompt();
 		rl_clear_message();
+		rl_set_prompt(".... ");
 	} else {
 		len += strlen(multiline);
 		s = xmalloc(len + 1);
@@ -89,13 +90,16 @@ static void cli_complete(char *line)
 	const char *c;
 	LIST_HEAD(msgs);
 
-	line = cli_append_multiline(line);
 	if (line == NULL) {
 		printf("\n");
 		cli_exit();
-		return;
+		exit(0);
 	}
 
+	line = cli_append_multiline(line);
+	if (line == NULL)
+		return;
+
 	for (c = line; *c != '\0'; c++)
 		if (!isspace(*c))
 			break;