date_api upgrade tries to rename a table to one that already exists

So I have found this weird issue that people stumbled upon before here and here. I understand the issue is mostly harmless when seen from the web interface, but for the user, it's still confusing and it still looks like an error. Furthermore, this makes this module impossible to migrate automatically inside Aegir and yields horrible red errors in drush.

Here is the actual problem:

 * user warning: Table 'date_formats' already exists query: ALTER TABLE date_format RENAME TO date_formats in /home/bric/public_html/includes/database.mysql-common.inc on line 249.
* user warning: Can't DROP 'format'; check that column/key exists query: ALTER TABLE date_formats DROP KEY format in /home/bric/public_html/includes/database.mysql-common.inc on line 417.
* user warning: Duplicate key name 'formats' query: ALTER TABLE date_formats ADD UNIQUE KEY formats (format, type) in /home/bric/public_html/includes/database.mysql-common.inc on line 403.

Update #6004

* Failed: ALTER TABLE {date_format} RENAME TO {date_formats}
* Failed: ALTER TABLE {date_formats} DROP KEY format
* Failed: ALTER TABLE {date_formats} ADD UNIQUE KEY formats (format, type)

The problem is that sometimes, for some weird reason, the date_formats table actually already exists alongside the other one. I have no idea how that happens and I'm not *too* interested in finding out why, but I know of a simple fix that would alleviate a lot of worries.