title: Recovering from a duplicate migration in Django South
body: <p>Due to merging several feature branches into my project, I have the following migrations:</p>
  
  <pre><code>0001_initial.py
  0002_auto__add_field_userprofile_telephone__add_field_userprofile_timezone.py
  0003_auto.py
  0004_auto__del_field_organisation_admin.py
  0005_auto__add_field_organisation_permitted_domains.py
  0005_auto__add_field_userprofile_currency.py
  </code></pre>
  
  <p>Note that I have two duplicate 0005 migrations. These ran fine, and deployed fine on my production system.</p>
  
  <pre><code>$ python manage.py migrate accounts --list                                                                                                                                                              [17:11:42]
  
   accounts
    (*) 0001_initial
    (*) 0002_auto__add_field_userprofile_telephone__add_field_userprofile_timezone
    (*) 0003_auto
    (*) 0004_auto__del_field_organisation_admin
    (*) 0005_auto__add_field_organisation_permitted_domains
    (*) 0005_auto__add_field_userprofile_currency
  </code></pre>
  
  <p>My table has the correct columns:</p>
  
  <pre><code>$ psql
  db_my_project=# \d+ accounts_organisation
  db_my_project=# \d+ accounts_userprofile
  ... shows currency and permitted_domain, suggesting the migrations worked correctly
  </code></pre>
  
  <p>However, if I try to create a new migration, South thinks that I haven't added the column' permitted_domains' to my model:</p>
  
  <pre><code>$ python manage.py schemamigration accounts --auto                                                                                                                                                      [17:16:15]
   + Added field permitted_domains on accounts.Organisation
  Created 0006_auto__add_field_organisation_permitted_domains.py. You can now apply this migration with: ./manage.py migrate accounts
  </code></pre>
  
  <p>How do I fix this?</p>