diff -r 0aeb81eb179c -r e7d348134006 server/test/unittest_migractions.py
--- a/server/test/unittest_migractions.py	Fri Aug 21 15:07:13 2009 +0200
+++ b/server/test/unittest_migractions.py	Fri Aug 21 15:07:47 2009 +0200
@@ -449,5 +449,47 @@
         user.clear_related_cache('in_state', 'subject')
         self.assertEquals(user.state, 'deactivated')
 
+    def test_introduce_base_class(self):
+        self.mh.cmd_add_entity_type('Para')
+        self.mh.repo.schema.rebuild_infered_relations()
+        self.assertEquals(sorted(et.type for et in self.schema['Para'].specialized_by()),
+                          ['Note'])
+        self.assertEquals(self.schema['Note'].specializes().type, 'Para')
+        self.mh.cmd_add_entity_type('Text')
+        self.mh.repo.schema.rebuild_infered_relations()
+        self.assertEquals(sorted(et.type for et in self.schema['Para'].specialized_by()),
+                          ['Note', 'Text'])
+        self.assertEquals(self.schema['Text'].specializes().type, 'Para')
+        # test columns have been actually added
+        text = self.execute('INSERT Text X: X para "hip", X summary "hop", X newattr "momo"').get_entity(0, 0)
+        note = self.execute('INSERT Note X: X para "hip", X shortpara "hop", X newattr "momo"').get_entity(0, 0)
+        aff = self.execute('INSERT Affaire X').get_entity(0, 0)
+        self.failUnless(self.execute('SET X newnotinlined Y WHERE X eid %(x)s, Y eid %(y)s',
+                                     {'x': text.eid, 'y': aff.eid}, 'x'))
+        self.failUnless(self.execute('SET X newnotinlined Y WHERE X eid %(x)s, Y eid %(y)s',
+                                     {'x': note.eid, 'y': aff.eid}, 'x'))
+        self.failUnless(self.execute('SET X newinlined Y WHERE X eid %(x)s, Y eid %(y)s',
+                                     {'x': text.eid, 'y': aff.eid}, 'x'))
+        self.failUnless(self.execute('SET X newinlined Y WHERE X eid %(x)s, Y eid %(y)s',
+                                     {'x': note.eid, 'y': aff.eid}, 'x'))
+        # XXX remove specializes by ourselves, else tearDown fails when removing
+        # Para because of Note inheritance. This could be fixed by putting the
+        # MemSchemaCWETypeDel(session, name) operation in the
+        # after_delete_entity(CWEType) hook, since in that case the MemSchemaSpecializesDel
+        # operation would be removed before, but I'm not sure this is a desired behaviour.
+        #
+        # also we need more tests about introducing/removing base classes or
+        # specialization relationship...
+        self.session.data['rebuild-infered'] = True
+        try:
+            self.execute('DELETE X specializes Y WHERE Y name "Para"')
+            self.commit()
+        finally:
+            self.session.data['rebuild-infered'] = False
+        self.assertEquals(sorted(et.type for et in self.schema['Para'].specialized_by()),
+                          [])
+        self.assertEquals(self.schema['Note'].specializes(), None)
+        self.assertEquals(self.schema['Text'].specializes(), None)
+
 if __name__ == '__main__':
     unittest_main()