+git symbolic-ref HEAD >../sym.before
+git rev-parse HEAD >../ref.before
+
+$fixup --real
+
+git symbolic-ref HEAD >../sym.after
+git rev-parse HEAD >../ref.after
+diff ../sym.before ../sym.after
+set +e; diff ../ref.before ../ref.after; rc=$?; set -e; test $rc = 1