[RFC PATCH v2 10/11] filter-branch: invoke post-rewrite hook

@@ -12,7 +12,7 @@ SYNOPSIS
 	[--index-filter <command>] [--parent-filter <command>]
 	[--msg-filter <command>] [--commit-filter <command>]
 	[--tag-name-filter <command>] [--subdirectory-filter <directory>]
-	[--prune-empty]
+	[--prune-empty] [--post-rewrite <command>]
 	[--original <namespace>] [-d <directory>] [-f | --force]
 	[--] [<rev-list options>...]
 

@@ -182,6 +182,11 @@ the nearest ancestor that was not excluded.
 	of the `git commit-tree "$@"` idiom in your commit filter to make that
 	happen.
 
+--post-rewrite <command>::
+	Overrides the post-rewrite hook (if you have one).  To bypass
+	the hook for this invocation, pass `:`.  See
+	linkgit:githooks[1].
+
 --original <namespace>::
 	Use this option to set the namespace where the original commits
 	will be stored. The default value is 'refs/original'.

@@ -101,6 +101,7 @@ USAGE="[--env-filter <command>] [--tree-filter <command>]
             [--index-filter <command>] [--parent-filter <command>]
             [--msg-filter <command>] [--commit-filter <command>]
             [--tag-name-filter <command>] [--subdirectory-filter <directory>]
+	    [--post-rewrite <command>]
             [--original <namespace>] [-d <directory>] [-f | --force]
             [<rev-list options>...]"
 

@@ -126,6 +127,13 @@ orig_namespace=refs/original/
 force=
 prune_empty=
 remap_to_ancestor=
+
+if test -x "$GIT_DIR"/hooks/post-rewrite; then
+	post_rewrite=$(git rev-parse --sq-quote "$GIT_DIR"/hooks/post-rewrite)
+else
+	post_rewrite=:
+fi
+
 while :
 do
 	case "$1" in

@@ -190,6 +198,10 @@ do
 		filter_subdir="$OPTARG"
 		remap_to_ancestor=t
 		;;
+	--post-rewrite)
+		post_rewrite="$OPTARG"
+		post_rewrite_given=t
+		;;
 	--original)
 		orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
 		;;

@@ -358,6 +370,10 @@ while read commit parents; do
 	@SHELL_PATH@ -c "$filter_commit" "git commit-tree" \
 		$(git write-tree) $parentstr < ../message > ../map/$commit ||
 			die "could not write rewritten commit"
+	new_commit=$(map $commit)
+	if test $commit != $new_commit; then
+		echo $commit $new_commit >> "$workdir"/../rewritten
+	fi
 done <../revs
 
 # If we are filtering for paths, as in the case of a subdirectory

@@ -484,6 +500,11 @@ if [ "$filter_tag_name" ]; then
 fi
 
 cd ../..
+
+if test -s "$workdir"/../rewritten; then
+	eval "$post_rewrite" 'filter-branch < "$workdir"/../rewritten'
+fi
+
 rm -rf "$tempdir"
 
 trap - 0

@@ -157,4 +157,32 @@ EOF
 	verify_hook_input
 '
 
+test_expect_success 'git filter-branch' '
+	git reset --hard D &&
+	clear_hook_input &&
+	git filter-branch -f --tree-filter "touch newfile" B..HEAD &&
+	echo filter-branch >expected.args &&
+	cat >expected.data <<EOF &&
+$(git rev-parse C) $(git rev-parse HEAD^)
+$(git rev-parse D) $(git rev-parse HEAD)
+EOF
+	verify_hook_input
+'
+
+test_expect_success 'git filter-branch (no-op)' '
+	git reset --hard D &&
+	clear_hook_input &&
+	git filter-branch -f B..HEAD &&
+	test ! -f post-rewrite.args &&
+	test ! -f post-rewrite.data
+'
+
+test_expect_success 'git filter-branch --post-rewrite :' '
+	git reset --hard D &&
+	clear_hook_input &&
+	git filter-branch -f --post-rewrite : --tree-filter "touch newfile" B..HEAD &&
+	test ! -f post-rewrite.args &&
+	test ! -f post-rewrite.data
+'
+
 test_done