ircd-irc2: disable netsplit detection

By default ircd goes to netsplit mode if the amount of connected
users or servers go below a certain limit.

Default limits are less than 65000 users connected or less than 80
servers connected. This means that in practice all brew installed
ircds are always in netsplit mode.

In netsplit mode no one can be channel operator. Channel operators
are useful already in small ircd setups. Therefore it's best to
disable netsplit detection. You need to administrate a popular IRC
network with multiple servers for netsplit detection to be useful.

Closes Homebrew/homebrew#29993.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Formula/ircd-irc2.rb

@@ -34,8 +34,17 @@ class IrcdIrc2 < Formula
                           "--mandir=#{man}",
                           "CFLAGS=-DRLIMIT_FDMAX=0"
 
+    build_dir = `./support/config.guess`.chomp
+
+    # Disable netsplit detection. In a netsplit, joins to new channels do not
+    # give chanop status.
+    inreplace "#{build_dir}/config.h", /#define DEFAULT_SPLIT_USERS\s+65000/,
+      "#define DEFAULT_SPLIT_USERS 0"
+    inreplace "#{build_dir}/config.h", /#define DEFAULT_SPLIT_SERVERS\s+80/,
+      "#define DEFAULT_SPLIT_SERVERS 0"
+
     # The directory is something like `i686-apple-darwin13.0.2'
-    system "make", "install", "-C", `./support/config.guess`.chomp
+    system "make", "install", "-C", build_dir
 
     (etc/"ircd.conf").write default_ircd_conf
   end