[FIX] website_form: public user can send attachment

Issue:
An additional information page is part of our shop process to allow
additional information to be submitted. If this form is left blank,
then selecting the next button allows the process to continue.
However, if data is added to the form the form freezes and the process
will not continue when 'next' is selected.

Why:
Public user can not read the field 'model' of 'ir.model' (to save the
attachments)

opw-1818592

addons/website_form/controllers/main.py

@@ -170,7 +170,8 @@ class WebsiteForm(http.Controller):
         return data
 
     def insert_record(self, request, model, values, custom, meta=None):
-        record = request.env[model.model].sudo().with_context(mail_create_nosubscribe=True).create(values)
+        model_name = model.sudo().model
+        record = request.env[model_name].sudo().with_context(mail_create_nosubscribe=True).create(values)
 
         if custom or meta:
             default_field = model.website_form_default_field_id
@@ -182,13 +183,13 @@ class WebsiteForm(http.Controller):
             # If there is a default field configured for this model, use it.
             # If there isn't, put the custom data in a message instead
             if default_field.name:
-                if default_field.ttype == 'html' or model.model == 'mail.mail':
+                if default_field.ttype == 'html' or model_name == 'mail.mail':
                     custom_content = nl2br(custom_content)
                 record.update({default_field.name: custom_content})
             else:
                 values = {
                     'body': nl2br(custom_content),
-                    'model': model.model,
+                    'model': model_name,
                     'message_type': 'comment',
                     'no_auto_thread': False,
                     'res_id': record.id,
@@ -200,7 +201,8 @@ class WebsiteForm(http.Controller):
     # Link all files attached on the form
     def insert_attachment(self, model, id_record, files):
         orphan_attachment_ids = []
-        record = model.env[model.model].browse(id_record)
+        model_name = model.sudo().model
+        record = model.env[model_name].browse(id_record)
         authorized_fields = model.sudo()._get_form_writable_fields()
         for file in files:
             custom_field = file.field_name not in authorized_fields
@@ -208,7 +210,7 @@ class WebsiteForm(http.Controller):
                 'name': file.field_name if custom_field else file.filename,
                 'datas': base64.encodestring(file.read()),
                 'datas_fname': file.filename,
-                'res_model': model.model,
+                'res_model': model_name,
                 'res_id': record.id,
             }
             attachment_id = request.env['ir.attachment'].sudo().create(attachment_value)
@@ -220,10 +222,10 @@ class WebsiteForm(http.Controller):
         # If some attachments didn't match a field on the model,
         # we create a mail.message to link them to the record
         if orphan_attachment_ids:
-            if model.model != 'mail.mail':
+            if model_name != 'mail.mail':
                 values = {
                     'body': _('<p>Attached files : </p>'),
-                    'model': model.model,
+                    'model': model_name,
                     'message_type': 'comment',
                     'no_auto_thread': False,
                     'res_id': id_record,