Fix #5415 - Deleted comments get removed properly when tombstones

The original wrapper existed and should be been removed, this fix
now ensures the TextComment removes the Comment wrapper to prevent
the deleted (comments which are tombstones) existing.

mediagoblin/db/models.py

@@ -1008,6 +1008,17 @@ class TextComment(Base, TextCommentMixin, CommentingMixin):
                                               cascade="all, delete-orphan"))
     deletion_mode = Base.SOFT_DELETE
 
+    def soft_delete(self, *args, **kwargs):
+        # Find the GMR for this model.
+        gmr = GenericModelReference.query.filter_by(
+            obj_pk=self.id,
+            model_type=self.__tablename__
+        ).first()
+
+        # Delete the Comment object for this comment
+        Comment.query.filter_by(comment_id=gmr.id).delete()
+        return super(TextComment, self).soft_delete(*args, **kwargs)
+
     def serialize(self, request):
         """ Unserialize to python dictionary for API """
         target = self.get_reply_to()

mediagoblin/tests/test_misc.py

@@ -138,3 +138,34 @@ def test_garbage_collection_task(test_app):
 
     # Now validate the image has been deleted
     assert MediaEntry.query.filter_by(id=entry_id).first() is None
+
+def test_comments_removed_when_graveyarded(test_app):
+    """ Checks comments which are tombstones are removed from collection """
+    user = fixture_add_user()
+    media = fixture_media_entry(
+        uploader=user.id,
+        expunge=False,
+        fake_upload=False
+    )
+    
+    # Add the TextComment
+    comment = TextComment()
+    comment.actor = user.id
+    comment.content = u"This is a comment that will be deleted."
+    comment.save()
+
+    # Add a link for the comment
+    link = Comment()
+    link.target = media
+    link.comment = comment
+    link.save()
+
+    # First double check it's there and all is well...
+    assert Comment.query.filter_by(target_id=link.target_id).first() is not None
+
+    # Now delete the comment.
+    comment.delete()
+
+    # Verify this also deleted the Comment link, ergo there is no comment left.
+    assert Comment.query.filter_by(target_id=link.target_id).first() is None
+