#!/bin/rc 

rfork e

if(! ~ $#* 1){
	echo 'usage: patch/apply patch-name' >[1=2]
	exit usage
}
. /rc/bin/patch/defs
mountfs

test -e /n/dist/386 || bind  /root /n/dist || fail no dist

test -e /n/dist/386 || fail /root/386 does not exist

{touch  /n/dist/lib/XXX && rm -f /n/dist/lib/XXX } >[2]/dev/null|| fail no permission to write /n/dist/lib

d=$PD/$1
if(! patch/okay $d){
	echo 'bad patch: '$status >[1=2]
	exit badpatch
}

if(test -e /n/dist/lib/patch.skip && grep -s '^'^$1^'$' /n/dist/lib/patch.skip){
	echo patch $1 is a skip. done. >[1=2]
	exit ''
}

echo  /dist/patch/$1
if(! test -d /n/dist/dist/patch/$1){
	must mkdir -p /n/dist/dist/patch/$1
	must dircp $d /n/dist/dist/patch/$1
}
d=/n/dist/dist/patch/$1
must cd $d

echo -n merge... >[1=2]
fn xxx {
	rm -rf $2.new
	if(! test -e /n/dist$1 && test -e $2.orig){
		echo $1 'locally removed (ignoring)'>[1=2]
	}
	if(test -e /n/dist$1 && ! test -e $2.orig){
		echo fail: $1 locally created. remove and retry>[1=2]
		touch failed
	}
	if(test -f /n/dist$1 && test -d $2.orig){
		echo $1 is now a file.>[1=2]
		touch failed
	}
	if(test -d /n/dist$1 && test -f $2.orig){
		echo $1 is now a directory>[1=2]
		touch failed
	}
	if(test -f /n/dist$1 && test -f $2.orig){
		errs=/tmp/apply.$pid
		ape/diff3 -m /n/dist$1 $2.orig $2 >$2.new >[2]$errs
		if(grep -s 'Binary' $errs){
			rm -f $2.new
			if(! cmp /n/dist$1 $2.orig>[2]/dev/null){
				echo conflicts in binary file $1';' see `{pwd} >[1=2]
				touch failed
			}
		}
		if not{
			if(grep -s '^<<<<' $2.new){
				echo conflicts merging $1';' see `{pwd}^/$2.new >[1=2]
				touch failed
			}
		}
		rm -f $errs
	}
	if(test -d /n/dist$1 && test -d $2.orig){
		diff -ncr /n/dist$1 $2.orig >$2.diffs
		if(grep -s '^diff '  $2.diffs){
			echo conflicts merging $1';' see `{pwd}^/$2.diffs >[1=2]
			touch failed
		}
		if not {
			mkdir -p $2.new
			dircp $2.orig $2.new
			dircp $2 $2.new
		}
	}
}
rm -f failed
cat files | sed 's/^/xxx /' | rc
if(test -f failed){
	echo exiting without changes >[1=2]
	rm -f failed
	exit failed
}

echo -n backup... >[1=2]

fn xxx {
	rm -rf $2.backup
	test -e /n/dist$1 && cpfile /n/dist$1 $2.backup
}
rm -f failed
cat files | sed 's/^/xxx /' |rc
if(test -f failed){
	echo exiting without changes cannot backup: `{cat failed}>[1=2]
	rm -f failed
	exit failed
}
echo  copy... >[1=2]
rm -f failed
fn xxx {
	echo cpfile $2 /n/dist$1 >[1=2]
	if(test -e $2.new)
		cpfile $2.new /n/dist$1
	if not
		cpfile $2 /n/dist$1
	#BUG: update /n/dist/$1 permissions by looking at those of $2.orig
}
cat files | sed 's/^/xxx /' | rc

fn xxx {
	# echo cp $2.backup $1
	if(test -e $2.backup)
		cpfile $2.backup /n/dist$1
	if not
		rm -rf /n/dist$1
}
if(test -f failed){
	echo copying failed, restoring backups >[1=2]
	cat files | sed 's/^/xxx /' | rc
	exit failed
}

if(test -s removed){
	echo '#' remove these files if you want. I will not remove them for you >[1=2]
	echo '# (patch/undo will not restore them)'>[1=2]
	sed 's/^/rm -rf /' < removed
}
echo done>[1=2]