Fix exception when message limit is hit

app/controllers/message_controller.rb

@@ -28,10 +28,10 @@ class MessageController < ApplicationController
           redirect_to :controller => 'message', :action => 'inbox', :display_name => @user.display_name
         end
       end
-    else
-      @message = Message.new(:recipient => @this_user)
-      @title = t 'message.new.title'
     end
+
+    @message ||= Message.new(:recipient => @this_user)
+    @title = t 'message.new.title'
   end
 
   # Allow the user to reply to another message.

test/controllers/message_controller_test.rb

@@ -134,6 +134,27 @@ class MessageControllerTest < ActionController::TestCase
     assert_select "h1", "The user non_existent_user does not exist"
   end
 
+  ##
+  # test the new action message limit
+  def test_new_limit
+    # Login as a normal user
+    session[:user] = users(:normal_user).id
+
+    # Check that sending a message fails when the message limit is hit
+    assert_no_difference "ActionMailer::Base.deliveries.size" do
+      assert_no_difference "Message.count" do
+        with_message_limit(0) do
+          post :new,
+            :display_name => users(:public_user).display_name,
+            :message => { :title => "Test Message", :body => "Test message body" }
+          assert_response :success
+          assert_template "new"
+          assert_select "p.error", /wait a while/
+        end
+      end
+    end
+  end
+
   ##
   # test the reply action
   def test_reply
@@ -362,4 +383,16 @@ class MessageControllerTest < ActionController::TestCase
     assert_response :not_found
     assert_template "no_such_message"
   end
+
+private
+
+  def with_message_limit(value)
+    max_messages_per_hour = Object.send("remove_const", "MAX_MESSAGES_PER_HOUR")
+    Object.const_set("MAX_MESSAGES_PER_HOUR", value)
+
+    yield
+
+    Object.send("remove_const", "MAX_MESSAGES_PER_HOUR")
+    Object.const_set("MAX_MESSAGES_PER_HOUR", max_messages_per_hour)
+  end
 end