Failing test and fix for running take_over twice.

branch.sql

@@ -0,0 +1,20 @@
+DELETE FROM participants WHERE username = ANY( ARRAY[
+        '4c46cc22afdd',
+        '82b0d81fe9e8',
+        '6b6527ac6c02',
+        'cbde8c31c11c',
+        'bcfc65158eaf',
+        '31d54a0c19ae',
+        'afbddadaac3c',
+        'a78c4e42bb93',
+        '42eb93b3ab89',
+        'b1bc5e47fe8e',
+        '3ac515cc8da6',
+        '14a79340c40d',
+        '14d60c6884e7',
+        '0c783dee50ed',
+        'e2020536ef6d',
+        '60a5099d49c7',
+        '64f4f959b322',
+        '0bdf90d51786',
+        '880ac6873f7f']);

gittip/models/__init__.py

@@ -108,29 +108,7 @@ def _check_orphans(self):
               where not exists (select * from elsewhere where elsewhere.participant=username)
                 and not exists (select * from absorptions where archived_as=username)
         """)
-        known = set((
-            "4c46cc22afdd",
-            "82b0d81fe9e8",
-            "6b6527ac6c02",
-            "cbde8c31c11c",
-            "bcfc65158eaf",
-            "31d54a0c19ae",
-            "afbddadaac3c",
-            "a78c4e42bb93",
-            "42eb93b3ab89",
-            "b1bc5e47fe8e",
-            "3ac515cc8da6",
-            "14a79340c40d",
-            "14d60c6884e7",
-            "0c783dee50ed",
-            "e2020536ef6d",
-            "60a5099d49c7",
-            "64f4f959b322",
-            "0bdf90d51786",
-            "880ac6873f7f"
-        ))
-        real = set(orphans) - known
-        assert len(real) == 0, "missing elsewheres: {}".format(list(real))
+        assert len(orphans) == 0, "missing elsewheres: {}".format(list(orphans))
 
     def _check_orphans_no_tips(self):
         """

gittip/models/_mixin_elsewhere.py

@@ -269,6 +269,10 @@ def take_over(self, account_elsewhere, have_confirmation=False):
 
             other_username = rec.participant
 
+            if self.username == other_username:
+                # this is a no op - trying to take over itself
+                return
+
 
             # Make sure we have user confirmation if needed.
             # ==============================================

tests/test_participant.py

@@ -167,6 +167,14 @@ def test_do_not_take_over_zero_tips_receiving(self):
         assert 2 == ntips
         self.db.self_check()
 
+    def test_idempotent(self):
+        alice = TwitterAccount(self.db, 1, dict(screen_name='alice'))
+        bob   = GitHubAccount(self.db, 2, dict(screen_name='bob'))
+        alice_participant = alice.opt_in('alice')[0].participant
+        alice_participant.take_over(bob, have_confirmation=True)
+        alice_participant.take_over(bob, have_confirmation=True)
+        self.db.self_check()
+
 
 class TestParticipant(Harness):
     def setUp(self):