id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
27044	`apps` passed to post_migrate_signal should have access to migrated apps even when no migration has been applied to them	tkhyn	nobody	"Hi,

I noticed that when one runs `migrate` without arguments (implicitly migrating all apps), the `apps` instance passed to `emit_post_migrate_signal` (https://github.com/django/django/blob/1.10/django/core/management/commands/migrate.py#L221 [here]) contains the migrated apps' configurations only in the first run. 

On subsequent runs, the `plan` list ([https://github.com/django/django/blob/1.10/django/core/management/commands/migrate.py#L136 here]) is empty and `post_migrate_apps` is set to `pre_migrate_apps` ([https://github.com/django/django/blob/1.10/django/core/management/commands/migrate.py#L197 here]), i.e. the unmigrated apps.

For example, when calling `migrate` with the `contenttypes` app enabled, this means that `update_contenttypes` ([https://github.com/django/django/blob/1.10/django/contrib/contenttypes/management.py#L89 here]) is passed an `apps` instance with `contenttypes` missing. The consequence is that `update_contenttypes` can not go further than [https://github.com/django/django/blob/1.10/django/contrib/contenttypes/management.py#L102 this line].

To temporarily fix the issue and correctly trigger the `post_migrate_signal` so that the content types are properly updated, I need to run `flush` just after `migrate`. I don't think it should not be needed to run `flush` simply to correctly trigger the `post_migrate_signal` that will update the content types.

It worked fine in Django 1.9.9 as no project state apps instance is passed to `emit_post_migrate_signal`, and `update_contenttypes` uses the global `apps` instance.

I don't really know enough about the recent developments regarding apps management in Django, so I'm not sure what should be done to solve this issue. Thanks in advance if somebody has the time to look at it.

''Context: I'm testing a reusable django app ([https://bitbucket.org/tkhyn/django-gm2m django-gm2m]) which test suite includes migration tests for a number of mini test apps with different models (see [https://bitbucket.org/tkhyn/django-gm2m/src/63af327624a45c5aed110546d3d705a6b1bf7c2b/tests/?at=release here]). Whenever I switch to another mini-app, the database needs not only to be flushed but also re-migrated and the contenttypes need to be updated !.''"	Bug	new	Migrations	1.10	Normal				Unreviewed	0	0	0	0	0	0