Management commands should not specify the default value twice

[Paul McMillan]

Many of the management commands have a code pattern that seems likely to invite errors:

In the base of the Command class, they define options, including default values like this:

class Command(BaseCommand):
    option_list = BaseCommand.option_list + (
        make_option('--format', default='json', dest='format',
            help='Specifies the output serialization format for fixtures.'),

Then later on in the handle method, they get the option value, specifying a new default value if the option is not found, like this:

    def handle(self, *app_labels, **options):
        format = options.get('format','json')

This second default value is an error. Using optparse means that we are certain to receive a value for each option (it defaults to None). Using options.get() with a default value is redundant. Trying to get a non-existent option should throw an error, not return a default value.

Most of the management commands need this cleanup.

[Adam Vandenberg]

Remove duplicated default option values.

[Adam Vandenberg]

Rebased against trunk.

[Ramiro Morales]

See also #10080 and #14909.

[Claude Paroz]

Rebased against trunk (once again)

[Julien Phalip]

In [17028]:

Fixed #13760 -- Cleaned up unnecessary default option handling in a bunch of management commands. Thanks to Paul McMillan for the report and to adamv and Claude Paroz for the patch.

[Ramiro Morales]

In [17678]:

Fixed #17820 -- Fixed more occurrences of redundant handling of management commands options.

They had been missen in the first attempts or had been introduced afterwards.

Refs #13760, #10080, #17799.