[FIX] mail: standardize way to get guest from context

Backport of `_get_guest_from_context`.

Prevent crash when unexpected (not recordset) values are in the context.

Ensure the mere existence of a value (example integer) does not lead to
executing flows where an actual guest is expected.

task-2819597

closes odoo/odoo#127831

X-original-commit: 3d1890e88b99f059377d8b227b56d77798157397
Signed-off-by: Matthieu Stockbauer (tsm) <tsm@odoo.com>
Signed-off-by: Sébastien Theys (seb) <seb@odoo.com>

addons/mail/models/ir_http.py

@@ -13,7 +13,7 @@ class IrHttp(models.AbstractModel):
         result = super(IrHttp, self).session_info()
         if self.env.user._is_internal():
             result['notification_type'] = user.notification_type
-        guest = self.env.context.get('guest')
+        guest = self.env['mail.guest']._get_guest_from_context()
         if not request.session.uid and guest:
             user_context = {'lang': guest.lang}
             mods = odoo.conf.server_wide_modules or []

addons/mail/models/mail_message.py

@@ -197,10 +197,11 @@ class Message(models.Model):
     @api.depends_context('guest', 'uid')
     def _compute_is_current_user_or_guest_author(self):
         user = self.env.user
+        guest = self.env['mail.guest']._get_guest_from_context()
         for message in self:
             if not user._is_public() and (message.author_id and message.author_id == user.partner_id):
                 message.is_current_user_or_guest_author = True
-            elif user._is_public() and (message.author_guest_id and message.author_guest_id == self.env.context.get('guest')):
+            elif message.author_guest_id and message.author_guest_id == guest:
                 message.is_current_user_or_guest_author = True
             else:
                 message.is_current_user_or_guest_author = False

addons/mail/models/mail_thread.py

@@ -2023,8 +2023,9 @@ class MailThread(models.AbstractModel):
         self = self._fallback_lang()
 
         # Find the message's author
-        if self.env.user._is_public() and 'guest' in self.env.context:
-            author_guest_id = self.env.context['guest'].id
+        guest = self.env['mail.guest']._get_guest_from_context()
+        if self.env.user._is_public() and guest:
+            author_guest_id = guest.id
             author_id, email_from = False, False
         else:
             author_guest_id = False

addons/mail/models/res_partner.py

@@ -245,7 +245,7 @@ class Partner(models.Model):
                     "id": main_user.id,
                     "isInternalUser": not main_user.share,
                 } if main_user else [('clear',)]
-            if 'guest' in self.env.context or not self.env.user._is_internal():
+            if not self.env.user._is_internal():
                 data.pop('email', None)
             partners_format[partner] = data
         return partners_format