Add "git repack" command that does an incremental pack

Makefile

@@ -31,7 +31,7 @@ SCRIPTS=git git-apply-patch-script git-merge-one-file-script git-prune-script \
 	git-fetch-script git-status-script git-commit-script \
 	git-log-script git-shortlog git-cvsimport-script git-diff-script \
 	git-reset-script git-add-script git-checkout-script git-clone-script \
-	gitk git-cherry git-rebase-script git-relink-script
+	gitk git-cherry git-rebase-script git-relink-script git-repack-script
 
 PROG=   git-update-cache git-diff-files git-init-db git-write-tree \
 	git-read-tree git-commit-tree git-cat-file git-fsck-cache \

git-repack-script

@@ -0,0 +1,18 @@
+#!/bin/sh
+: ${GIT_DIR=.git}
+: ${GIT_OBJECT_DIRECTORY="$GIT_DIR/objects"}
+packname=$(date +"pack-%s")
+if [ -f "$GIT_OBJECT_DIRECTORY/pack/$packname.idx" ]; then
+	echo Pack $packname already exists
+	exit 1
+fi
+rm -f $packname.idx $packname.pack
+git-rev-list --unpacked --objects $(git-rev-parse --all) |
+	git-pack-objects --non-empty --incremental $packname ||
+	exit 1
+
+if [ ! -f $packname.idx ]; then
+	echo Nothing new to pack
+	exit 0
+fi
+mv $packname.idx $packname.pack "$GIT_OBJECT_DIRECTORY/pack/"