[FIX] really uninstall modules and avoid a crash on cached data

[FIX] don't try to uninstall uninstalled modules

[DEL] weird code

[FIX] actually cleanup where we can

database_cleanup/models/purge_models.py

@@ -10,11 +10,9 @@ class IrModel(models.Model):
     _inherit = 'ir.model'
 
     def _drop_table(self):
-        # Allow to skip this step during model unlink
-        # The super method crashes if the model cannot be instantiated
-        if self.env.context.get('no_drop_table'):
-            return True
-        return super(IrModel, self)._drop_table()
+        """this function crashes for undefined models"""
+        existing_model_ids = self.filtered(lambda x: x.model in self.env)
+        return super(IrModel, existing_model_ids)._drop_table()
 
     @api.depends()
     def _inherited_models(self):
@@ -28,11 +26,9 @@ class IrModelFields(models.Model):
 
     @api.multi
     def _prepare_update(self):
-        # Allow to skip this step during model unlink
-        # The super method crashes if the model cannot be instantiated
-        if self.env.context.get('no_prepare_update'):
-            return True
-        return super(IrModelFields, self)._prepare_update()
+        """this function crashes for undefined models"""
+        existing = self.filtered(lambda x: x.model in self.env)
+        return super(IrModelFields, existing)._prepare_update()
 
 
 class CleanupPurgeLineModel(models.TransientModel):
@@ -50,9 +46,7 @@ class CleanupPurgeLineModel(models.TransientModel):
         """
         context_flags = {
             MODULE_UNINSTALL_FLAG: True,
-            'no_drop_table': True,
             'purge': True,
-            'no_prepare_update': True,
         }
 
         if self:

database_cleanup/models/purge_modules.py

@@ -3,7 +3,6 @@
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
 from odoo import _, api, fields, models
 from odoo.exceptions import UserError
-from odoo.modules.registry import RegistryManager
 from odoo.modules.module import get_module_path
 from odoo.addons.base.ir.ir_model import MODULE_UNINSTALL_FLAG
 
@@ -41,25 +40,19 @@ class CleanupPurgeLineModule(models.TransientModel):
         Uninstall modules upon manual confirmation, then reload
         the database.
         """
-        if self:
-            objs = self
-        else:
-            objs = self.env['cleanup.purge.line.module']\
-                .browse(self._context.get('active_ids'))
-        module_names = objs.filtered(lambda x: not x.purged).mapped('name')
+        module_names = self.filtered(lambda x: not x.purged).mapped('name')
         modules = self.env['ir.module.module'].search([
             ('name', 'in', module_names)
         ])
         if not modules:
             return True
         self.logger.info('Purging modules %s', ', '.join(module_names))
-        modules.button_uninstall()
-        # we need this commit because reloading the registry would roll back
-        # our changes
-        self.env.cr.commit()  # pylint: disable=invalid-commit
-        RegistryManager.new(self.env.cr.dbname, update_module=True)
+        modules.filtered(
+            lambda x: x.state not in ('uninstallable', 'uninstalled')
+        ).button_immediate_uninstall()
+        modules.refresh()
         modules.unlink()
-        return objs.write({'purged': True})
+        return self.write({'purged': True})
 
 
 class CleanupPurgeWizardModule(models.TransientModel):