[FIMP] base: remove all translations when writing False

This "bugprovement" resolve the old issue of writing on a translatable
field a falsy value.

Before this commit, only the translation value was removed. When no
translation is present (or when the value is not set), the value is
retrieved directly from the source field.

Before 18d9c2cab2, it was still possible to go around this issue by
removing manually all ir.translation entries and writing with a user
in en_US.
This is no longer possible as writing on a translatable field always
uses translations when in multi-language environment, without
exception of en_US.

When writing a falsy value on a field, the expected behaviour is to
reset the value and see that falsy value after saving, not the old
value stored on the source model.

Remove all translations and force to update the column.

Removing one individual translation is still possible in the
translation popup.

Task id: 2062415

closes odoo/odoo#37077

Signed-off-by: Martin Trigaux (mat) <mat@odoo.com>

odoo/addons/base/tests/test_translate.py

@@ -481,6 +481,58 @@ class TestTranslationWrite(TransactionCase):
         ])
       
 
+    def test_05_remove_multi(self):
+        self.env['res.lang'].load_lang('fr_FR')
+
+        langs = self.env['res.lang'].get_installed()
+        self.assertEqual([('en_US', 'English (US)'), ('fr_FR', 'French / Français')], langs,
+            "Test did not started with expected languages")
+
+        belgium = self.env.ref('base.be')
+        # vat_label is translatable and not required
+        belgium.with_context(lang='en_US').write({'vat_label': 'VAT'})
+
+        # create translations if not exists
+        self.env['ir.translation']._upsert_translations([{
+            'type': 'model',
+            'name': 'res.country,vat_label',
+            'lang': 'en_US',
+            'res_id': belgium.id,
+            'src': 'VAT',
+            'value': 'VAT',
+            'state': 'translated',
+        }, {
+            'type': 'model',
+            'name': 'res.country,vat_label',
+            'lang': 'fr_FR',
+            'res_id': belgium.id,
+            'src': 'VAT',
+            'value': 'TVA',
+            'state': 'translated',
+        }])
+
+        # remove the value
+        belgium.with_context(lang='fr_FR').write({'vat_label': False})
+        # should recover the initial value from db
+        self.assertEqual(
+            False, belgium.with_context(lang='fr_FR').vat_label,
+            "Value was not reset"
+        )
+        self.assertEqual(
+            False, belgium.with_context(lang='en_US').vat_label,
+            "Value was not reset in other languages"
+        )
+        self.assertEqual(
+            False, belgium.with_context(lang=None).vat_label,
+            "Value was not reset on the field model"
+        )
+
+        translations = self.env['ir.translation'].search([
+            ('name', '=', 'res.country,vat_label'),
+            ('res_id', '=', belgium.id),
+        ])
+        self.assertEqual(len(translations), 0, "Translations were not removed")
+
     def test_field_selection(self):
         """ Test translations of field selections. """
         field = self.env['ir.model']._fields['state']

odoo/fields.py

@@ -1435,8 +1435,8 @@ class _String(Field):
                 update_column = True
                 update_trans = True
             elif lang != 'en_US':
-                # update the translations only
-                update_column = False
+                # update the translations only except if emptying
+                update_column = cache_value is None
                 update_trans = True
 
         # update towrite if modifying the source
@@ -1445,7 +1445,7 @@ class _String(Field):
             for rid in real_recs._ids:
                 # cache_value is already in database format
                 towrite[rid][self.name] = cache_value
-            if self.translate is True:
+            if self.translate is True and cache_value is not None:
                 tname = "%s,%s" % (records._name, self.name)
                 records.env['ir.translation']._set_source(tname, real_recs._ids, value)
 
@@ -1464,7 +1464,13 @@ class _String(Field):
                     source_recs[self.name] = value
                     source_value = value
                 tname = "%s,%s" % (self.model_name, self.name)
-                if single_lang:
+                if value is None:
+                    records.env['ir.translation'].search([
+                        ('name', '=', tname),
+                        ('type', '=', 'model'),
+                        ('res_id', 'in', real_recs._ids)
+                    ]).unlink()
+                elif single_lang:
                     records.env['ir.translation']._update_translations([dict(
                         src=source_value,
                         value=value,