Update to use the recommended recovery procedure from nvi-1.76.

This is a lot more robust and handles errors a lot better.  It also cleans
up stray, hopeless, or unmodified files rather than leaving them there
forever.

etc/rc

@@ -1,5 +1,5 @@
 #!/bin/sh
-#	$Id: rc,v 1.102 1996/10/21 20:09:30 wpaul Exp $
+#	$Id: rc,v 1.103 1996/10/28 08:28:02 joerg Exp $
 #	From: @(#)rc	5.27 (Berkeley) 6/5/91
 
 # System startup script run by init on autoboot
@@ -341,12 +341,43 @@ if [ -f /etc/rc.${arch} ]; then
 fi
 
 # Recover vi editor files.
-virecovery=`echo /var/tmp/vi.recover/recover.*`
-if [ "$virecovery" != '/var/tmp/vi.recover/recover.*' ]; then
+vibackup=`echo /var/tmp/vi.recover/vi.*`
+if [ "$vibackup" != '/var/tmp/vi.recover/vi.*' ]; then
 	echo 'Recovering vi editor sessions'
-	for i in $virecovery; do
-		sendmail -t < $i
+	for i in $vibackup; do
+		# Only test files that are readable.
+		if test ! -r $i; then
+			continue
+		fi
+
+		# Unmodified nvi editor backup files either have the
+		# execute bit set or are zero length.  Delete them.
+		if test -x $i -o ! -s $i; then
+			rm -f $i
+		fi
 	done
+
+	# It is possible to get incomplete recovery files, if the editor
+	# crashes at the right time.
+	virecovery=`echo /var/tmp/vi.recover/recover.*`
+	if [ "$virecovery" != "/var/tmp/vi.recover/recover.*" ]; then
+		for i in $virecovery; do
+			# Only test files that are readable.
+			if test ! -r $i; then
+				continue
+			fi
+
+			# Delete any recovery files that are zero length,
+			# corrupted, or that have no corresponding backup file.
+			# Else send mail to the user.
+			recfile=`awk '/^X-vi-recover-path:/{print $2}' < $i`
+			if test -n "$recfile" -a -s "$recfile"; then
+				sendmail -t < $i
+			else
+				rm -f $i
+			fi
+		done
+	fi
 fi
 
 # for each valid dir in $local_startup, search for init scripts matching *.sh