Allow the path to the system source directory to be passed in to

newvers.sh.  Pass it in from include/Makefile.  If it isn't passed in,
fall back to the old logic of using dirname $0.

Using dirname $0 does not yield the path to the script if it was
sourced in from another script in another directory; you end up with
the parent script's path.  That was causing newvers.sh to look one
level below the FreeBSD src/ directory when building osreldate.h and it
may find something like a git or svn repo there that has nothing to do
with FreeBSD.

PR:		174422
Approved by:	re ()
MFC after:	2 weeks

include/Makefile

@@ -104,8 +104,9 @@ SHARED?=	copies
 
 INCS+=	osreldate.h
 
-NEWVERS_SH=		${.CURDIR}/../sys/conf/newvers.sh
-PARAM_H=		${.CURDIR}/../sys/sys/param.h
+SYSDIR=			${.CURDIR}/../sys
+NEWVERS_SH=		${SYSDIR}/conf/newvers.sh
+PARAM_H=		${SYSDIR}/sys/param.h
 MK_OSRELDATE_SH=	${.CURDIR}/mk-osreldate.sh
 
 osreldate.h vers.c: ${NEWVERS_SH} ${PARAM_H} ${MK_OSRELDATE_SH}
@@ -113,6 +114,7 @@ osreldate.h vers.c: ${NEWVERS_SH} ${PARAM_H} ${MK_OSRELDATE_SH}
 	    MAKE="${MAKE}" \
 	    NEWVERS_SH=${NEWVERS_SH} \
 	    PARAM_H=${PARAM_H} \
+	    SYSDIR=${SYSDIR} \
 	    sh ${MK_OSRELDATE_SH}
 
 .for i in ${LHDRS}

sys/conf/newvers.sh

@@ -38,7 +38,10 @@ if [ "X${BRANCH_OVERRIDE}" != "X" ]; then
 fi
 RELEASE="${REVISION}-${BRANCH}"
 VERSION="${TYPE} ${RELEASE}"
-SYSDIR=$(dirname $0)/..
+
+if [ "X${SYSDIR}" = "X" ]; then
+    SYSDIR=$(dirname $0)/..
+fi
 
 if [ "X${PARAMFILE}" != "X" ]; then
 	RELDATE=$(awk '/__FreeBSD_version.*propagated to newvers/ {print $3}' \