$NetBSD$

Fix a possible SIGSEGV when doing:

 /bind ^I command_completion
 /^I

NUMBER_OF_COMMANDS should be decreased by 2 for `cmd_cnt' in the special case
for the empty string because:

 - We should omit the first command in irc_command[] (via the `command++' line
   before cmd_cnt assignment)
 - We should also omit the last NULL command in irc_command[].

--- source/edit.c.orig	2017-07-04 06:48:25.000000000 +0000
+++ source/edit.c
@@ -2403,7 +2403,7 @@ command_completion(u_int key, u_char *pt
 				if (*(command[0].name) == '\0')
 				{
 					command++;
-					cmd_cnt = NUMBER_OF_COMMANDS;
+					cmd_cnt = NUMBER_OF_COMMANDS - 2;
 				}
 			}
 			if ((alias_cnt == 1) && (cmd_cnt == 0))