Merge branch 'jk/filter-branch-sha256'

Code clean-up.

* jk/filter-branch-sha256:
  filter-branch: drop $_x40 glob
  filter-branch: drop multiple-ancestor warning
  t7003: test ref rewriting explicitly

git-filter-branch.sh

@@ -492,14 +492,12 @@ then
 		sha1=$(git rev-parse "$ref"^0)
 		test -f "$workdir"/../map/$sha1 && continue
 		ancestor=$(git rev-list --simplify-merges -1 "$ref" "$@")
-		test "$ancestor" && echo $(map $ancestor) >> "$workdir"/../map/$sha1
+		test "$ancestor" && echo $(map $ancestor) >"$workdir"/../map/$sha1
 	done < "$tempdir"/heads
 fi
 
 # Finally update the refs
 
-_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
-_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
 echo
 while read ref
 do
@@ -519,7 +517,7 @@ do
 		git update-ref -m "filter-branch: delete" -d "$ref" $sha1 ||
 			die "Could not delete $ref"
 	;;
-	$_x40)
+	*)
 		echo "Ref '$ref' was rewritten"
 		if ! git update-ref -m "filter-branch: rewrite" \
 					"$ref" $rewritten $sha1 2>/dev/null; then
@@ -533,16 +531,6 @@ do
 			fi
 		fi
 	;;
-	*)
-		# NEEDSWORK: possibly add -Werror, making this an error
-		warn "WARNING: '$ref' was rewritten into multiple commits:"
-		warn "$rewritten"
-		warn "WARNING: Ref '$ref' points to the first one now."
-		rewritten=$(echo "$rewritten" | head -n 1)
-		git update-ref -m "filter-branch: rewrite to first" \
-				"$ref" $rewritten $sha1 ||
-			die "Could not rewrite $ref"
-	;;
 	esac
 	git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1 ||
 		 exit

t/t7003-filter-branch.sh

@@ -506,4 +506,35 @@ test_expect_success 'rewrite repository including refs that point at non-commit
 	! fgrep fatal filter-output
 '
 
+test_expect_success 'filter-branch handles ref deletion' '
+	git switch --orphan empty-commit &&
+	git commit --allow-empty -m "empty commit" &&
+	git tag empty &&
+	git branch to-delete &&
+	git filter-branch -f --prune-empty to-delete >out 2>&1 &&
+	grep "to-delete.*was deleted" out &&
+	test_must_fail git rev-parse --verify to-delete
+'
+
+test_expect_success 'filter-branch handles ref rewrite' '
+	git checkout empty &&
+	test_commit to-drop &&
+	git branch rewrite &&
+	git filter-branch -f \
+		--index-filter "git rm --ignore-unmatch --cached to-drop.t" \
+		 rewrite >out 2>&1 &&
+	grep "rewrite.*was rewritten" out &&
+	! grep -i warning out &&
+	git diff-tree empty rewrite
+'
+
+test_expect_success 'filter-branch handles ancestor rewrite' '
+	test_commit to-exclude &&
+	git branch ancestor &&
+	git filter-branch -f ancestor -- :^to-exclude.t >out 2>&1 &&
+	grep "ancestor.*was rewritten" out &&
+	! grep -i warning out &&
+	git diff-tree HEAD^ ancestor
+'
+
 test_done