diff --git a/tests/test-revlog-packentry b/tests/test-revlog-packentry
new file mode 100755
--- /dev/null
+++ b/tests/test-revlog-packentry
@@ -0,0 +1,14 @@
+#!/bin/sh
+
+hg init repo
+cd repo
+
+touch foo
+hg ci -Am 'add foo'
+
+hg up -C null
+# this should be stored as a delta against rev 0
+echo foo bar baz > foo
+hg ci -Am 'add foo again'
+
+hg debugindex .hg/store/data/foo.i