--- /dev/null
+#!/bin/bash
+set -e
+set -o pipefail
+find -name .git -type d -exec sh -xec '
+ cd "$1"
+ git for-each-ref \
+ --format='\''update refs/dgit-test-keep/g%(objectname) %(objectname)'\'' \
+' x "{}" \; | \
+ sort -u | git update-ref --stdin