fixes #2822: Post vote API: returns 200 for both success and failure; fixes bug with x-api-limit header

app/models/comment.rb

@@ -109,14 +109,12 @@ class Comment < ActiveRecord::Base
   module VoteMethods
     def vote!(val)
       numerical_score = val == "up" ? 1 : -1
-      vote = votes.create(:score => numerical_score)
+      vote = votes.create!(:score => numerical_score)
 
-      if vote.errors.empty?
-        if vote.is_positive?
-          update_column(:score, score + 1)
-        elsif vote.is_negative?
-          update_column(:score, score - 1)
-        end
+      if vote.is_positive?
+        update_column(:score, score + 1)
+      elsif vote.is_negative?
+        update_column(:score, score - 1)
       end
 
       return vote

app/models/post.rb

@@ -1075,7 +1075,7 @@ class Post < ActiveRecord::Base
         raise PostVote::Error.new("You have already voted for this post")
       end
 
-      PostVote.create(:post_id => id, :score => score)
+      PostVote.create!(:post_id => id, :score => score)
       reload # PostVote.create modifies our score. Reload to get the new score.
     end