[FIX] website_forum: prevent calling vote on multi

This method was supposed to work in multi (see history) but that
behavior was lost somewhere.

Voting for several posts at the same time doesn't mean much in the end
and the function wouldn't work anyway because:

1. Return values wouldn't work in multi
2. It would try to vote n times for each of the n posts in self and
  violate unique constraint.
3. If the last existing vote had opposed value to the new vote,
  the method would create only '0'-valued votes for all the new
  records.

We here then clean it make sure it is not called on several posts.

A test is extended to check votes and records counts.

Task-3267872

closes odoo/odoo#123725

X-original-commit: dc049ce98292e08f5ecf2f20005dc227375dde75
Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>
Signed-off-by: Florian Charlier (flch) <flch@odoo.com>

addons/website_forum/models/forum_post.py

@@ -612,22 +612,19 @@ class Post(models.Model):
         return False
 
     def vote(self, upvote=True):
+        self.ensure_one()
         Vote = self.env['forum.post.vote']
-        vote_ids = Vote.search([('post_id', 'in', self._ids), ('user_id', '=', self._uid)])
-        new_vote = '1' if upvote else '-1'
-        voted_forum_ids = set()
-        if vote_ids:
-            for vote in vote_ids:
-                if upvote:
-                    new_vote = '0' if vote.vote == '-1' else '1'
-                else:
-                    new_vote = '0' if vote.vote == '1' else '-1'
-                vote.vote = new_vote
-                voted_forum_ids.add(vote.post_id.id)
-        for post_id in set(self._ids) - voted_forum_ids:
-            for post_id in self._ids:
-                Vote.create({'post_id': post_id, 'vote': new_vote})
-        return {'vote_count': self.vote_count, 'user_vote': new_vote}
+        existing_vote = Vote.search([('post_id', '=', self.id), ('user_id', '=', self._uid)])
+        new_vote_value = '1' if upvote else '-1'
+        if existing_vote:
+            if upvote:
+                new_vote_value = '0' if existing_vote.vote == '-1' else '1'
+            else:
+                new_vote_value = '0' if existing_vote.vote == '1' else '-1'
+            existing_vote.vote = new_vote_value
+        else:
+            Vote.create({'post_id': self.id, 'vote': new_vote_value})
+        return {'vote_count': self.vote_count, 'user_vote': new_vote_value}
 
     def convert_answer_to_comment(self):
         """ Tools to convert an answer (forum.post) to a comment (mail.message).

addons/website_forum/tests/test_forum_karma_access.py

@@ -373,10 +373,50 @@ class TestForumKarma(TestForumCommon):
         self.assertEqual(post.state, 'active', 'website_forum: wrong state when validate a post after offensive')
 
     def test_vote(self):
+        def check_vote_records_count_and_integrity(expected_total_votes_count):
+            groups = self.env['forum.post.vote'].read_group([], fields=['__count'], groupby=['post_id', 'user_id'], lazy=False)
+            self.assertEqual(len(groups), expected_total_votes_count)
+            for post_user_group in groups:
+                self.assertEqual(post_user_group['__count'], 1)
+
+        check_vote_records_count_and_integrity(2)
         self.post.create_uid.karma = KARMA['ask']
-        self.user_portal.karma = KARMA['upv']
-        self.post.with_user(self.user_portal).vote(upvote=True)
-        self.assertEqual(self.post.create_uid.karma, KARMA['ask'] + KARMA['gen_que_upv'], 'website_forum: wrong karma generation of upvoted question author')
+        self.user_portal.karma = KARMA['dwv']
+        initial_vote_count = self.post.vote_count
+        post_as_portal = self.post.with_user(self.user_portal)
+        res = post_as_portal.vote(upvote=True)
+
+        self.assertEqual(res['user_vote'], '1')
+        self.assertEqual(res['vote_count'], initial_vote_count + 1)
+        self.assertEqual(post_as_portal.user_vote, 1)
+        self.assertEqual(
+            self.post.create_uid.karma,
+            KARMA['ask'] + KARMA['gen_que_upv'],
+            'website_forum: wrong karma generation of upvoted question author',
+        )
+
+        # On voting again with the same value, nothing changes
+        res = post_as_portal.vote(upvote=True)
+        self.assertEqual(res['vote_count'], initial_vote_count + 1)
+        self.assertEqual(res['user_vote'], '1')
+        self.post.invalidate_recordset()
+        self.assertEqual(post_as_portal.user_vote, 1)
+
+        # On reverting vote, vote cancels
+        res = post_as_portal.vote(upvote=False)
+        self.assertEqual(res['vote_count'], initial_vote_count)
+        self.assertEqual(res['user_vote'], '0')
+        self.post.invalidate_recordset()
+        self.assertEqual(post_as_portal.user_vote, 0)
+
+        # Everything works from "0" too
+        res = post_as_portal.vote(upvote=False)
+        self.assertEqual(res['vote_count'], initial_vote_count - 1)
+        self.assertEqual(res['user_vote'], '-1')
+        self.post.invalidate_recordset()
+        self.assertEqual(post_as_portal.user_vote, -1)
+
+        check_vote_records_count_and_integrity(3)
 
     @mute_logger('odoo.addons.base.models.ir_model', 'odoo.models')
     def test_vote_crash(self):