[FIX] core: avoid invalidation of field 'ir.ui.view.arch' when setting it

This fixes the following issue.  Set the field `arch` on a view; this
automatically writes on `arch_db`, which is a translated field.  If some
translations are discarded, a call to `unlink()` invalidates the whole
cache.  And then things go wrong: when `arch_db` is validated, the field
`arch` is missing from cache, and the ORM sets it to `None` because the
field is still protected by the initial write!

Fix the issue by avoiding the call to `unlink()`, and do it in SQL
instead.

closes odoo/odoo#45740

X-original-commit: e7679152ee480a51ef2b6d208ae7a05b2ef61941
Signed-off-by: Raphael Collet (rco) <rco@openerp.com>

odoo/addons/base/models/ir_translation.py

@@ -445,7 +445,14 @@ class IrTranslation(models.Model):
 
         # process outdated and discarded translations
         outdated.write({'state': 'to_translate'})
-        discarded.unlink()
+
+        if discarded:
+            # delete in SQL to avoid invalidating the whole cache
+            discarded._modified()
+            discarded.modified(self._fields)
+            self.flush(self._fields, discarded)
+            self.invalidate_cache(ids=discarded._ids)
+            self.env.cr.execute("DELETE FROM ir_translation WHERE id IN %s", [discarded._ids])
 
     @api.model
     @tools.ormcache_context('model_name', keys=('lang',))

odoo/addons/base/tests/test_views.py

@@ -236,6 +236,32 @@ class TestViewInheritance(ViewCase):
                 'arch': self.arch_for('itself', parent=True),
             })
 
+    def test_write_arch(self):
+        self.env['res.lang']._activate_lang('fr_FR')
+
+        v = self.makeView("T", arch='<form string="Foo">Bar</form>')
+        self.env['ir.translation']._upsert_translations([{
+            'type': 'model_terms',
+            'name': 'ir.ui.view,arch_db',
+            'lang': 'fr_FR',
+            'res_id': v.id,
+            'src': 'Foo',
+            'value': 'Fou',
+        }, {
+            'type': 'model_terms',
+            'name': 'ir.ui.view,arch_db',
+            'lang': 'fr_FR',
+            'res_id': v.id,
+            'src': 'Bar',
+            'value': 'Barre',
+        }])
+        self.assertEqual(v.arch, '<form string="Foo">Bar</form>')
+
+        # modify v to discard translations; this should not invalidate 'arch'!
+        v.arch = '<form></form>'
+        self.assertEqual(v.arch, '<form></form>')
+
+
 class TestApplyInheritanceSpecs(ViewCase):
     """ Applies a sequence of inheritance specification nodes to a base
     architecture. IO state parameters (cr, uid, model, context) are used for