filter-branch: drop $_x40 glob

When checking whether a commit was rewritten to a single object id, we
use a glob that insists on a 40-hex result. This works for sha1, but
fails t7003 when run with GIT_TEST_DEFAULT_HASH=sha256.

Since the previous commit simplified the case statement here, we only
have two arms: an empty string or a single object id. We can just loosen
our glob to match anything, and still distinguish those cases (we lose
the ability to notice bogus input, but that's not a problem; we are the
one who wrote the map in the first place, and anyway update-ref will
complain loudly if the input isn't a valid hash).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: peff

git-filter-branch.sh

@@ -498,8 +498,6 @@ 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 $sha1 2>/dev/null; then
@@ -533,9 +531,6 @@ do
 			fi
 		fi
 	;;
-	*)
-		die "BUG: multiple ancestors in map file?"
-	;;
 	esac
 	git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1 ||
 		 exit