[FIX] core: allow write translation for non-existing record

before this commit:
    record = env['model.name'].browse(id)
if record doesn't exist in the database and call
   record.translated_field_name = value
Then _get_stored_translation will raise
   TypeError: 'NoneType' object is not subscriptable

after this commit:
like write non-translated field, the value can be written to the cache, but not
the database and no error will be raised.
Note: The feature is only for the original ORM 'write', if the 'overriden write'
reads other fields of the non-existing record, a MissingError will be raised.

closes odoo/odoo#119202

X-original-commit: 3ba7ca28a68acccb8eb25f117900c1aa1980264a
Signed-off-by: Raphael Collet <rco@odoo.com>
Signed-off-by: Wang Chong (cwg) <cwg@odoo.com>

odoo/addons/base/tests/test_translate.py

@@ -696,7 +696,7 @@ class TestTranslationWrite(TransactionCase):
         self.assertEqual(belgium.with_context(lang='en_US').vat_label, '')
         self.assertEqual(belgium.with_context(lang='nl_NL').vat_label, '')
 
-    def test_cresate_emtpy_false(self):
+    def test_create_empty_false(self):
         self._test_create_empty(False)
 
     # feature removed
@@ -1040,6 +1040,21 @@ class TestXMLTranslation(TransactionCase):
         self.assertEqual(view.with_context(lang='fr_FR').arch_db, '<form string="X">Pain et fromage<div>Fourchette2</div></form>')
         self.assertEqual(view.with_context(lang='nl_NL').arch_db, view_nl)
 
+
+class TestHTMLTranslation(TransactionCase):
+    def test_write_non_existing(self):
+        html = '''
+<h1>My First Heading</h1>
+<p>My first paragraph.</p>
+'''
+        company = self.env['res.company'].browse(9999)
+        company.report_footer = html
+        self.assertHTMLEqual(company.report_footer, html)
+        # flushing on non-existing records does not break for scalar fields; the
+        # same behavior is expected for translated fields
+        company.flush_recordset()
+
+
 @tagged('post_install', '-at_install')
 class TestLanguageInstallPerformance(TransactionCase):
     def test_language_install(self):

odoo/fields.py

@@ -1738,7 +1738,8 @@ class _String(Field):
         record.flush_recordset([self.name])
         cr = record.env.cr
         cr.execute(f'SELECT "{self.name}" FROM "{record._table}" WHERE id = %s', (record.id,))
-        return cr.fetchone()[0]
+        res = cr.fetchone()
+        return res[0] if res else None
 
     def write(self, records, value):
         if not self.translate or value is False or value is None: