Make gc a builtin.

Signed-off-by: James Bowes <jbowes@dangerouslyinc.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>

contrib/examples/git-gc.sh

@@ -0,0 +1,37 @@
+#!/bin/sh
+#
+# Copyright (c) 2006, Shawn O. Pearce
+#
+# Cleanup unreachable files and optimize the repository.
+
+USAGE='[--prune]'
+SUBDIRECTORY_OK=Yes
+. git-sh-setup
+
+no_prune=:
+while case $# in 0) break ;; esac
+do
+	case "$1" in
+	--prune)
+		no_prune=
+		;;
+	--)
+		usage
+		;;
+	esac
+	shift
+done
+
+case "$(git config --get gc.packrefs)" in
+notbare|"")
+	test $(is_bare_repository) = true || pack_refs=true;;
+*)
+	pack_refs=$(git config --bool --get gc.packrefs)
+esac
+
+test "true" != "$pack_refs" ||
+git-pack-refs --prune &&
+git-reflog expire --all &&
+git-repack -a -d -l &&
+$no_prune git-prune &&
+git-rerere gc || exit