new file mode 100755
--- /dev/null
+++ b/tests/test-issue522
@@ -0,0 +1,31 @@
+#!/bin/sh
+
+# In the merge below, the file "foo" has the same contents in both
+# parents, but if we look at the file-level history, we'll notice that
+# the version in p1 is an ancestor of the version in p2.  This test
+# makes sure that we'll use the version from p2 in the manifest of the
+# merge revision.
+
+hg init repo
+cd repo
+
+echo foo > foo
+hg ci -d '0 0' -qAm 'add foo'
+
+echo bar >> foo
+hg ci -d '0 0' -m 'change foo'
+
+hg backout -d '0 0' -r tip -m 'backout changed foo'
+
+hg up -C 0
+touch bar
+hg ci -d '0 0' -qAm 'add bar'
+
+hg merge --debug
+hg debugstate | grep foo
+hg st -A foo
+hg ci -d '0 0' -m 'merge'
+
+hg manifest --debug | grep foo
+hg debugindex .hg/store/data/foo.i
+