[FIX] website_forum: fix post/forum website URL computation on memory records

'slug' cannot be called on records which are not yet saved, aka have no ID.
In this commit we set the website_url to False for records that do not have
any ID.

Code managing those URLs is updated to be defensive, as notably when using
studio you may end up trying to call methods on in-memory records.

Followup of odoo/odoo@da3f4c2aff

Task-3254382

closes odoo/odoo#117255

X-original-commit: 36c734ab37fdf1d6a245e0e29cfefe3cc46c6d92
Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>

addons/website_forum/models/forum_forum.py

@@ -181,7 +181,9 @@ class Forum(models.Model):
     # EXTENDS WEBSITE.MULTI.MIXIN
 
     def _compute_website_url(self):
-        return '/forum/%s' % (slug(self))
+        if not self.id:
+            return False
+        return f'/forum/{slug(self)}'
 
     # ----------------------------------------------------------------------
     # CRUD
@@ -261,6 +263,9 @@ class Forum(models.Model):
 
     def go_to_website(self):
         self.ensure_one()
+        website_url = self._compute_website_url
+        if not website_url:
+            return False
         return self.env['website'].get_client_action(self._compute_website_url())
 
     @api.model

addons/website_forum/models/forum_post.py

@@ -172,8 +172,9 @@ class Post(models.Model):
 
     @api.depends('name')
     def _compute_website_url(self):
-        for post in self:
-            anchor = post.parent_id and '#answer_%d' % post.id or ''
+        self.website_url = False
+        for post in self.filtered(lambda post: post.id):
+            anchor = f'#answer_{post.id}' if post.parent_id else ''
             post.website_url = f'/forum/{slug(post.forum_id)}/{slug(post)}{anchor}'
 
     @api.depends('vote_count', 'forum_id.relevancy_post_vote', 'forum_id.relevancy_time_decay')
@@ -793,6 +794,8 @@ class Post(models.Model):
 
     def go_to_website(self):
         self.ensure_one()
+        if not self.website_url:
+            return False
         return self.env['website'].get_client_action(self.website_url)
 
     @api.model