[PATCH] make git-prune-script actually work

[James Bottomley <James.Bottomley@SteelEye.com>]

I find this script very useful to get back to where I started from after
test merges, and also for cloning trees from a non-current base.  The
functionality is altered so it now takes an optional commit argument
(and a -q flag to make it be quiet).

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

--- a/git-prune-script
+++ b/git-prune-script
@@ -1,2 +1,23 @@
 #!/bin/sh
-fsck-cache --unreachable $(cat .git/HEAD ) | grep unreachable | cut -d' ' -f3 | sed 's:^\(..\):.git/objects/\1/:' | xargs rm
+verbose=true
+case $1 in 
+	-q)	verbose=false
+		shift;;
+esac
+head=$1
+if [ -z "$head" ]; then
+	head=$(cat .git/HEAD)
+fi
+f=$(fsck-cache --unreachable $head | awk '/^unreachable /{print $3}'| sed 's:^\(..\):.git/objects/\1/:')
+if [ -z "$f" ]; then
+	echo "Nothing to remove"
+	exit 0
+fi
+
+for g in $f; do
+	if $verbose; then
+		echo $g
+	fi
+	rm -f $g
+done
+echo $head > .git/HEAD