Add a patch:

- stop using mlock as it requires root credential
- call ev_loop_fork so that forking actually works with kqueue

x11/i3lock/Makefile

@@ -1,13 +1,9 @@
-# New ports collection makefile for:	i3lock
-# Date created:		2009-05-22
-# Whom:			Dennis Herrmann <dhn@FreeBSD.org>
-#
+# Created by: Dennis Herrmann <dhn@FreeBSD.org>
 # $FreeBSD$
-#
 
 PORTNAME=	i3lock
 PORTVERSION=	2.4.1
-PORTREVISION=	1
+PORTREVISION=	2
 CATEGORIES=	x11
 MASTER_SITES=	http://i3wm.org/${PORTNAME}/ \
 		http://mirror.4bit.ws/ \

x11/i3lock/files/patch-i3lock.c

@@ -0,0 +1,40 @@
+--- ./i3lock.c.orig	2013-03-19 21:44:37.876383724 +0100
++++ ./i3lock.c	2013-03-20 19:23:55.060606716 +0100
+@@ -525,6 +525,8 @@
+                     /* In the parent process, we exit */
+                     if (fork() != 0)
+                         exit(0);
++
++                    ev_loop_fork(EV_DEFAULT);
+                 }
+                 break;
+ 
+@@ -645,11 +647,16 @@
+     if (ret != PAM_SUCCESS)
+         errx(EXIT_FAILURE, "PAM: %s", pam_strerror(pam_handle, ret));
+ 
++/* Using mlock() as non-super-user seems only possible in Linux. Users of other
++ * operating systems should use encrypted swap/no swap (or remove the ifdef and
++ * run i3lock as super-user). */
++#if defined(__linux__)
+     /* Lock the area where we store the password in memory, we don’t want it to
+      * be swapped to disk. Since Linux 2.6.9, this does not require any
+      * privileges, just enough bytes in the RLIMIT_MEMLOCK limit. */
+     if (mlock(password, sizeof(password)) != 0)
+         err(EXIT_FAILURE, "Could not lock page in memory, check RLIMIT_MEMLOCK");
++#endif
+ 
+     /* Initialize connection to X11 */
+     if ((conn = xcb_connect(NULL, &nscreen)) == NULL ||
+@@ -731,9 +738,11 @@
+     ev_check_init(xcb_check, xcb_check_cb);
+     ev_check_start(main_loop, xcb_check);
+ 
++    ev_check_init(xcb_check, xcb_check_cb);
+     ev_prepare_init(xcb_prepare, xcb_prepare_cb);
+     ev_prepare_start(main_loop, xcb_prepare);
+ 
++    ev_check_init(xcb_check, xcb_check_cb);
+     /* Invoke the event callback once to catch all the events which were
+      * received up until now. ev will only pick up new events (when the X11
+      * file descriptor becomes readable). */