--- freebsd.eclass.orig	2012-11-24 20:31:14.000000000 +0900
+++ freebsd.eclass.orig	2013-02-21 20:34:57.000000000 +0900
@@ -6,6 +6,10 @@ 
 
 inherit versionator eutils flag-o-matic bsdmk
 
+# Drop patch level from ${PV}
+MY_PV=${PV/_p*}
+PLEVEL=${PV##*_p}
+
 LICENSE="BSD"
 HOMEPAGE="http://www.freebsd.org/"
 
@@ -27,7 +31,30 @@ 
 CDDL="freebsd-cddl-${PV}"
 
 # Release version (5.3, 5.4, 6.0, etc)
-RV="$(get_version_component_range 1-2)"
+RV="$(get_version_component_range 1-2 ${MY_PV})"
+
+# SVN ebuild support, details please see bug 458570.
+if [[ ${MY_PV} == *9999* ]]; then
+	inherit subversion
+
+	# Set SVN revision using patch level.
+	[[ ${PV} == *_p* ]] && ESVN_REVISION="${PLEVEL}"
+
+	# freebsd-mk-defs is always run svn checkout/update.
+	# Other packages use sources that it checked out.
+	[[ ${PN} == freebsd-mk-defs ]] || ESVN_OFFLINE="1"
+
+	case ${MY_PV%.9999} in
+		*.*.*)	BRANCH="release";;
+		*.*)	BRANCH="releng"	;;
+		9999)	BRANCH="head"	;;
+		*)	BRANCH="stable"	;;
+	esac
+	[[ ${BRANCH} == head ]] || SVN_SUB_URI="${BRANCH}/${MY_PV%.9999}"
+	[[ ${BRANCH} == head ]] && SVN_SUB_URI="${BRANCH}"
+	ESVN_REPO_URI="svn://svn.freebsd.org/base/${SVN_SUB_URI}"
+	ESVN_PROJECT="freebsd-${BRANCH}"
+fi
 
 if [[ ${PN} != "freebsd-share" ]] && [[ ${PN} != freebsd-sources ]]; then
 	IUSE="profile"
@@ -90,7 +117,11 @@ 
 }
 
 freebsd_src_unpack() {
-	unpack ${A}
+	if [[ ${MY_PV} == *9999* ]]; then
+		S="${WORKDIR}" subversion_src_unpack
+	else
+		unpack ${A}
+	fi
 	cd "${S}"
 
 	dummy_mk ${REMOVE_SUBDIRS}