COUNTRIES_ONLY and migrations.

[drozdowsky]

Let's say I have
country = CountryField(multiple=True)
somewhere in my open source project.
We have migration that has max_length=749.

But then someone adds (before running migration) COUNTRIES_ONLY=["US"].
Because of this settings the Django will migrate this to max_length=2 (instead of 749). If we remove this settings, no new migration will be made. We are stuck with max_length=2.

To add more:
multiple=True implementation could be better, we could use ArrayField (for postgres only).
max_length is only a DB validation option, it does not impact memory/storage use, if we really want to use CharField just omit max_length (use TextField).

[SmileyChris]

It does seem like a bug that there's no second migration made.

Using ArrayField for a specific DB, or TextField (which although is pretty much identical in Postgres, does have differences in MySQL) are neither options that I'm thrilled about