Merge /etc/mtree/special & /etc/mtree/special.local using "mtree -M".

This allows users to override mtree/special entries in mtree/special.local,
which is useful if you've replaced a directory with a symlink (for example).
This effectively makes $check_mtree_follow_symlinks=YES pointless, but
I'm retaining that for compatibility reasons.

Fix bug in generation of $MPBYUID (used "/^+/" instead of "/^\+/" as a regex),
which has existed for a long time but only failed with our awk; GNU awk seems
to have permitted this.  (This meant that the duplicate UID check was broken
when using our awk.)

Rename some temp files to more accurately reflect their purpose, to
aid debugging.

etc/security

@@ -1,6 +1,6 @@
 #!/bin/sh -
 #
-#	$NetBSD: security,v 1.90 2004/04/09 17:33:35 kim Exp $
+#	$NetBSD: security,v 1.91 2004/07/23 06:12:16 lukem Exp $
 #	from: @(#)security	8.1 (Berkeley) 6/9/93
 #
 
@@ -49,16 +49,17 @@ if ! cd "$SECUREDIR"; then
 	exit 1
 fi
 
-ERR=secure1.$$
-TMP1=secure2.$$
-TMP2=secure3.$$
-MPBYUID=secure4.$$
-MPBYPATH=secure5.$$
-LIST=secure6.$$
-OUTPUT=secure7.$$
-LABELS=secure8.$$
-PKGS=secure9.$$
-CHANGEFILES=secure10.$$
+ERR=err.$$
+TMP1=tmp1.$$
+TMP2=tmp2.$$
+MPBYUID=mpbyuid.$$
+MPBYPATH=mpbypath.$$
+LIST=list.$$
+OUTPUT=output.$$
+LABELS=labels.$$
+PKGS=pkgs.$$
+CHANGEFILES=changefiles.$$
+SPECIALSPEC=specialspec.$$
 
 
 # migrate_file old new
@@ -169,8 +170,11 @@ backup_and_diff()
 
 # These are used several times.
 #
-awk -F: '!/^+/ { print $1 " " $3 }' $MP | sort -k2n > $MPBYUID
+awk -F: '!/^\+/ { print $1 " " $3 }' $MP | sort -k2n > $MPBYUID
 awk -F: '{ print $1 " " $9 }' $MP | sort -k2 > $MPBYPATH
+for file in $special_files; do
+	[ -s $file ] && cat $file
+done | mtree -CM -k all > $SPECIALSPEC || exit 1
 
 
 # Check the master password file syntax.
@@ -756,10 +760,7 @@ if checkyesno check_mtree; then
 	else
 		check_mtree_flags=""
 	fi
-	for file in $special_files; do
-		[ ! -s $file ] && continue
-		mtree -e -l -p / $check_mtree_flags -f $file
-	done 3>&1 >$OUTPUT 2>&3 |
+	mtree -e -l -p / $check_mtree_flags -f $SPECIALSPEC 3>&1 >$OUTPUT 2>&3 |
 		grep -v '^mtree: dev/tty: Device not configured$' >&2
 	if [ -s $OUTPUT ]; then
 		printf "\nChecking special files and directories.\n"
@@ -834,11 +835,8 @@ fi
 # Any changes cause the files to rotate.
 #
 if checkyesno check_changelist ; then
-	for file in $special_files; do
-		[ ! -s $file ] && continue
-		mtree -D -k type -f $file -E exclude |
-		    sed '/^type=file/!d ; s/type=file \.//'
-	done > $CHANGEFILES
+	mtree -D -k type -f $SPECIALSPEC -E exclude |
+	    sed '/^type=file/!d ; s/type=file \.//' | unvis > $CHANGEFILES
 
 	(
 		# Add other files which might dynamically exist:
@@ -884,11 +882,8 @@ fi
 # differences and we don't want to do that for these files
 #
 echo $MP > $TMP1			# always add /etc/master.passwd
-for file in $special_files; do
-	[ ! -s $file ] && continue
-	mtree -D -k type -f $file -I nodiff |
-	    sed '/^type=file/!d ; s/type=file \.//'
-done >> $TMP1
+mtree -D -k type -f $SPECIALSPEC -I nodiff |
+    sed '/^type=file/!d ; s/type=file \.//' | unvis >> $TMP1
 grep -v '^$' $TMP1 | sort -u > $TMP2
 
 while read file; do