If the only manager on the model is the default manager defined
by Django (`objects = models.Manager()`), this manager will not
be added to the model state. If it is custom, it needs to be
passed to the model state.
This also prevents state modifications from corrupting previous states.
Previously, when a model defining a relation was unregistered first,
clearing the cache would cause its related models' _meta to be cleared
and would result in the old models losing track of their relations.
If Field.choices is provided as an iterator, consume it in __init__ instead
of using itertools.tee (which ends up holding everything in memory
anyway). Fixes a bug where deconstruct() was consuming the iterator but
bypassing the call to `tee`.
Swapped out models don't have a _default_manager unless they have
explicitly defined managers. ModelState.from_model() now accounts for
this case and uses an empty list for managers if no explicit managers
are defined and a model is swapped out.
When a related field is deleted, the related model must be updated. As
unchanged models are shared in migration states, the related model must
be re-rendered so that the change applies to a new copy of the related
model.
Thanks Henrik Heimbuerger for the report.
Made sure the app labels stay unique for the AppConfigStubs, so
migrations wouldn't fail if two dotted app names has the same last part
(e.g. django.contrib.auth and vendor.auth)
Changed the migration autodetector to remove models last so that FK
and M2M fields will not be left as dangling references. Added a check
in the migration state renderer to error out in the presence of
dangling references instead of leaving them as strings. Fixed a bug
in the sqlite backend to handle the deletion of M2M fields with
"through" models properly (i.e., do nothing successfully).
Thanks to melinath for report, loic for tests and andrewgodwin and
charettes for assistance with architecture.
Changed the migration autodetector to remove models last so that FK
and M2M fields will not be left as dangling references. Added a check
in the migration state renderer to error out in the presence of
dangling references instead of leaving them as strings. Fixed a bug
in the sqlite backend to handle the deletion of M2M fields with
"through" models properly (i.e., do nothing successfully).
Thanks to melinath for report, loic for tests and andrewgodwin and
charettes for assistance with architecture.
This commit reverts 69d4b1c and tackle the issue from a different angle.
Models remain present in the project state, but are now ignored by the
autodetector.
Improved Andrew's hack to create temporary app caches to handle
migrations. Now the main app cache has a "master" flag set to True
(which is a non-default keyword argument, thus unlikely to be used by
mistake). Other app cache instances have "master" set to False.
The only sanctioned way to access the app cache is by importing
django.core.apps.app_cache.
If you were instanciating an app cache and relying on the Borg pattern,
you'll have to refactor your code.
