remove dupes before correcting topic_ids in user action consistency check job

app/models/user_action.rb

@@ -215,6 +215,27 @@ ORDER BY p.created_at desc
 
   def self.synchronize_target_topic_ids(post_ids = nil)
 
+    # nuke all dupes, using magic
+    builder = SqlBuilder.new <<SQL
+DELETE FROM user_actions USING user_actions ua2
+/*where*/
+SQL
+
+    builder.where <<SQL
+  user_actions.action_type = ua2.action_type AND
+  user_actions.user_id = ua2.user_id AND
+  user_actions.acting_user_id = ua2.acting_user_id AND
+  user_actions.target_post_id = ua2.target_post_id AND
+  user_actions.target_post_id > 0 AND
+  user_actions.id > ua2.id
+SQL
+
+    if post_ids
+      builder.where("user_actions.target_post_id in (:post_ids)", post_ids: post_ids)
+    end
+
+    builder.exec
+
     builder = SqlBuilder.new("UPDATE user_actions
                     SET target_topic_id = (select topic_id from posts where posts.id = target_post_id)
                     /*where*/")

spec/models/user_action_spec.rb

@@ -273,10 +273,16 @@ describe UserAction do
         target_post_id: post.id,
       )
 
-      action.reload
-      action.target_topic_id.should == -1
+      UserAction.log_action!(
+        action_type: UserAction::NEW_PRIVATE_MESSAGE,
+        user_id: post.user.id,
+        acting_user_id: post.user.id,
+        target_topic_id: -2,
+        target_post_id: post.id,
+      )
 
       UserAction.ensure_consistency!
+
       action.reload
       action.target_topic_id.should == post.topic_id