makemigrations --update changes the name of custom migration name

[David Sanders]

This may be intentional behaviour but the docs don't mention this so creating a ticket to update docs or correct behaviour:

If you create a migration with a custom name:

$ ./manage.py makemigrations --name foo
Migrations for 'update_rename':
  update_rename/migrations/0001_foo.py
    - Create model Foo

then running --update will change the name "foo" to the autogenerated one based on the operations:

$ ./manage.py makemigrations --update
Migrations for 'update_rename':
  update_rename/migrations/0001_initial.py
    - Create model Foo
Deleted update_rename/migrations/0001_foo.py

My opinion is that it shouldn't as it violates the principle of least astonishment even though the --name argument wasn't supplied.