new file mode 100755
--- /dev/null
+++ b/tests/test-issue660
@@ -0,0 +1,89 @@
+#!/bin/sh
+# http://www.selenic.com/mercurial/bts/issue660
+
+
+hg init a
+cd a
+echo a > a
+mkdir b
+echo b > b/b
+hg commit -A -m "a is file, b is dir"
+
+echo % file replaced with directory
+
+rm a
+mkdir a
+echo a > a/a
+
+echo % should fail - would corrupt dirstate
+hg add a/a 
+
+echo % removing shadow
+hg rm --after a
+
+echo % should succeed - shadow removed
+hg add a/a
+
+echo % directory replaced with file
+
+rm -r b
+echo b > b
+
+echo % should fail - would corrupt dirstate
+hg add b
+
+echo % removing shadow
+hg rm --after b/b
+
+echo % should succeed - shadow removed
+hg add b
+
+echo % look what we got
+hg st
+
+echo % revert reintroducing shadow - should fail
+rm -r a b
+hg revert b/b
+
+echo % revert all - should succeed
+hg revert --all
+hg st
+
+echo % addremove
+
+rm -r a b
+mkdir a
+echo a > a/a
+echo b > b
+
+hg addremove
+hg st
+
+echo % commit
+hg ci -A -m "a is dir, b is file"
+hg st --all
+
+echo % long directory replaced with file
+
+mkdir d
+mkdir d/d
+echo d > d/d/d
+hg commit -A -m "d is long directory"
+rm -r d
+echo d > d
+
+echo % should fail - would corrupt dirstate
+hg add d
+
+echo % removing shadow
+hg rm --after d/d/d
+
+echo % should succeed - shadow removed
+hg add d
+
+#echo % update should work
+#
+#hg up -r 0
+#hg up -r 1
+
+exit 0