If flagging a topic with only one post, flag the post instead

app/models/post_action.rb

@@ -124,13 +124,18 @@ class PostAction < ActiveRecord::Base
 
     related_post_id = create_message_for_post_action(user,post,post_action_type_id,opts)
 
+    targets_topic = if opts[:flag_topic] and post.topic
+      post.topic.reload
+      post.topic.posts_count != 1
+    end
+
     create( post_id: post.id,
             user_id: user.id,
             post_action_type_id: post_action_type_id,
             message: opts[:message],
             staff_took_action: opts[:take_action] || false,
             related_post_id: related_post_id,
-            targets_topic: !!opts[:flag_topic] )
+            targets_topic: !!targets_topic )
   rescue ActiveRecord::RecordNotUnique
     # can happen despite being .create
     # since already bookmarked

spec/models/post_action_spec.rb

@@ -269,6 +269,21 @@ describe PostAction do
       post.hidden.should be_true
       post.hidden_reason_id.should == Post.hidden_reasons[:flag_threshold_reached_again]
     end
+
+    it "can flag the topic instead of a post" do
+      post1 = create_post
+      post2 = create_post(topic: post1.topic)
+      post_action = PostAction.act(Fabricate(:user), post1, PostActionType.types[:spam], {flag_topic: true})
+      post_action.targets_topic.should == true
+    end
+
+    it "will flag the first post if you flag a topic but there is only one post in the topic" do
+      post = create_post
+      post_action = PostAction.act(Fabricate(:user), post, PostActionType.types[:spam], {flag_topic: true})
+      post_action.targets_topic.should == false
+      post_action.post_id.should == post.id
+    end
+
   end
 
   it "prevents user to act twice at the same time" do