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.
The idea behind this change is, that AlterUniqueTogether,
AlterIndexTogether and AlterOrderWithRespectTo can always be moved after
an Add/Alter/Rename/RemoveField operation if they don't refer to the
respective field and are not empty sets / None.
Combined with the optimizations of duplicate AlterUniqueTogether,
AlterIndexTogether, and AlterOrderWithRespectTo operations from
128caa1e16, these operations are optimized
in a later round of the optimizer.
Thanks Tim Graham for the review.
This is a regression caused by introducing rendered migration states in
1aa3e09c20 and the _meta refactoring in fb48eb0581.
Thanks to Danilo Bargen for reporting the issue and Marten Kenbeek and
Tim Graham for triaging the bug and providing the initial test case.
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.
Calling Migration.mutate_state() now also allows to do in_place
mutations in case an intermediate state is thrown away later.
Thanks Anssi Kääriäinen for the idea, Ryan Hall for parts of the patch,
and Claude Paroz and Tim Graham for the review
Made MigrationGraph forwards_plan() and backwards_plan() fall back to an
iterative approach in case the recursive approach exceeds the recursion
depth limit.
This adds a new method, Apps.lazy_model_operation(), and a helper function,
lazy_related_operation(), which together supersede add_lazy_relation() and
make lazy model operations the responsibility of the App registry. This
system no longer uses the class_prepared signal.
Field.rel is now deprecated. Rel objects have now also remote_field
attribute. This means that self == self.remote_field.remote_field.
In addition, made the Rel objects a bit more like Field objects. Still,
marked ManyToManyFields as null=True.
Set apps.ready to False when rendering multiple models. This prevents
that the cache on Model._meta is expired on all models after each time a
single model is rendered. Prevented that Apps.clear_cache() refills the
cache on Apps.get_models(), so that the wrong value cannot be cached
when cloning a StateApps.
There's no reason to assume that sys.path[0] is an appropriate location
for generating code. Specifically that doesn't work with extend_sys_path
which puts the additional directories at the end of sys.path.
In order to create a new migrations module, instead of using an
arbitrary entry from sys.path, import as much as possible from the path
to the module, then create missing submodules from there.
Without this change, the tests introduced in the following commit fail,
which seems sufficient to prevent regressions for such a refactoring.
Kai Richard Koenig
Andriy Sokolovskiy
Markus Holtermann
Tim Graham
Steadman
Carl Meyer
Yoong Kang Lim
Matt Westcott
Marten Kenbeek
Piotr Jakimiak
Claude Paroz
Luis Del Giudice
Matthew Wilkes
Christopher Luc
Patryk Zawadzki
Baptiste Mispelon
Alex Hill
Anssi Kääriäinen
Aymeric Augustin