#! /bin/sh
# run in the wd of a tree to which the patch belongs
# depends on tla-diffrevs
#
# the optional second argument is a subdirectory that
# you want to get a patch for
# 

test "$1" = "-l" && {
	log=yes
	shift
}
patchno=${1?}
subdir=$2
test -x `dirname $0`/tla-diffrevs || exit 1
prev=`echo $patchno - 1 | bc`
if test "$prev" = "0"; then
	prev=base-0
else
	prev="patch-$prev"
fi
test "$subdir" && subdir="-d $subdir"

if test "$log" = "yes"; then
	tla changelog | awk -v target=$patchno '
	function pr(r) {
		if (patchno == target)
			print r
	}
	BEGIN { rec = "start"; patchno = "nope" }
	/^[0-9]/ {
		pr(rec)
		rec = ""
		patchno = substr($0, match($0, "[0-9]+$"))
	}
	{ rec = rec "\n" $0 }
	END { pr(rec) }'
fi

tla-diffrevs $subdir $prev patch-$patchno