IntegrityError raised merging people

[Diogo Matsubara]

As seen on OOPS-1626B636 an IntegrityError: duplicate key value violates unique constraint "account_openid_identifier_key" was raised while the user was trying to merge accounts.

[Curtis Hovey (sinzui)]

The user in this case created two profiles in the same day, possibly via two seperate logins from SSO. All 6 errors were cause by him from 3 different logintokens.

The code adds a 'merged-' prefix to the old account to prevent the OpenID identifier from being used. The identifier was unique. we are certain because of the '-' in the prefix, that it is not possible for it to be accicentally generated. The renamed identifier also exceeds the length of the generated identifier.

It is possible that the account identifier was once used, someone merge the account, This user got the same identifier, then tried a merge. This is a legitimate scenario, though I would have expected such an event to be unlikely to happen in 10 years--it happened in 2 weeks.

[Curtis Hovey (sinzui)]

I have looked at the data synced on staging and I can confirm that the openid identifier was indeed reused after it was freed and renamed to 'merged-*'. The code needs a mechanism to create a unique merged openid indentifier. I propose we use the datetime to ensure no collision.

[Ursula Junque (ursinha)]

Fixed in stable r11043 <http://bazaar.launchpad.net/~launchpad-pqm/launchpad/stable/revision/11043>.