[FIX] core: reinstall hooks after setting up models in registry

Before this patch, adding a field on a custom model discards all
automated actions on that model.  The explanation is relatively simple.
When models are set up in the registry, the classes of custom models are
dropped then recreated.  Given that automated actions are implemented as
monkey-patches on model classes, the setup of models simply loses those
monkey-patches, which explains why they stop working on custom models.

The fix introduces an `_unregister_hook()` method, that is expected to
clean up what has been done in `_register_hook()`.  When the registry is
ready (i.e., not being loaded), the setup of models first invokes
`_unregister_hook()` on models, proceeds with the setup, and finally
invokes `_register_hook()` to reinstall the hooks.

OPW 2362308

closes odoo/odoo#60833

X-original-commit: 67152bf82da2674179297d32e4cec9dd534fa0c9
Signed-off-by: Raphael Collet (rco) <rco@openerp.com>

odoo/models.py

@@ -4827,6 +4827,10 @@ Fields:
         """ stuff to do right after the registry is built """
         pass
 
+    def _unregister_hook(self):
+        """ Clean up what `~._register_hook` has done. """
+        pass
+
     @classmethod
     def _patch_method(cls, name, method):
         """ Monkey-patch a method for all instances of this model. This replaces

odoo/modules/loading.py

@@ -567,6 +567,10 @@ def load_modules(db, force_demo=False, status=None, update_module=False):
             _logger.error('At least one test failed when loading the modules.')
 
         # STEP 8: call _register_hook on every model
+        # This is done *exactly once* when the registry is being loaded. See the
+        # management of those hooks in `Registry.setup_models`: all the calls to
+        # setup_models() done here do not mess up with hooks, as registry.ready
+        # is False.
         env = api.Environment(cr, SUPERUSER_ID, {})
         for model in env.values():
             model._register_hook()

odoo/modules/registry.py

@@ -236,10 +236,17 @@ class Registry(Mapping):
         """ Complete the setup of models.
             This must be called after loading modules and before using the ORM.
         """
+        env = odoo.api.Environment(cr, SUPERUSER_ID, {})
+
+        # Uninstall registry hooks. Because of the condition, this only happens
+        # on a fully loaded registry, and not on a registry being loaded.
+        if self.ready:
+            for model in env.values():
+                model._unregister_hook()
+
         self.clear_caches()
         lazy_property.reset_all(self)
         self.registry_invalidated = True
-        env = odoo.api.Environment(cr, SUPERUSER_ID, {})
 
         if env.all.tocompute:
             _logger.error(
@@ -267,7 +274,12 @@ class Registry(Mapping):
         for model in models:
             model._setup_complete()
 
-        self.registry_invalidated = True
+        # Reinstall registry hooks. Because of the condition, this only happens
+        # on a fully loaded registry, and not on a registry being loaded.
+        if self.ready:
+            for model in env.values():
+                model._register_hook()
+            env['base'].flush()
 
     @lazy_property
     def field_computed(self):