irc: fix error message on /invite without arguments (bug #39272)

ChangeLog

@@ -1,7 +1,7 @@
 WeeChat ChangeLog
 =================
 Sébastien Helleu <flashcode@flashtux.org>
-v0.4.2-dev, 2013-06-29
+v0.4.2-dev, 2013-07-02
 
 
 This document lists all changes for each version.
@@ -30,6 +30,7 @@ Version 0.4.2 (under dev!)
 * core: fix line alignment when option weechat.look.buffer_time_format is set
   to empty string
 * aspell: add support of enchant library (patch #6858)
+* irc: fix error message on /invite without arguments (bug #39272)
 * irc: add support of special variables $nick/$channel/$server in commands
   /allchan and /allserv
 * irc: add option irc.look.nick_color_hash: hash algorithm to find nick color

src/plugins/irc/irc-command.c

@@ -1885,6 +1885,16 @@ irc_command_invite (void *data, struct t_gui_buffer *buffer, int argc,
     (void) data;
     (void) argv_eol;
 
+    if (argc < 2)
+    {
+        weechat_printf (NULL,
+                        _("%s%s: missing arguments for \"%s\" "
+                          "command"),
+                        weechat_prefix ("error"), IRC_PLUGIN_NAME,
+                        "invite");
+        return WEECHAT_RC_OK;
+    }
+
     if (argc > 2)
     {
         if (irc_channel_is_channel (ptr_server, argv[argc - 1]))