Temporary Nuclear option on topic titles - disallow non ascii characters so we

can stay on top of the trolls. This is meant to be replaced soon with a more
permissive and safe method of sanitizing.

app/models/topic.rb

@@ -24,6 +24,7 @@ class Topic < ActiveRecord::Base
   serialize :meta_data, ActiveRecord::Coders::Hstore
 
   validate :unique_title
+  validate :nuclear_option
 
   belongs_to :category
   has_many :posts
@@ -112,6 +113,21 @@ class Topic < ActiveRecord::Base
     errors.add(:title, I18n.t(:has_already_been_used)) if finder.exists?
   end
 
+  # This is bad, but people are screwing us on try.discourse.org - soon we'll replace with
+  # a much more sane validation of odd characters to allow for other languages and such.
+  def nuclear_option
+    
+    # Let presence validation catch it if it's blank
+    return if title.blank?
+
+    title.each_char do |c|
+      unless (20..126).include?(c.ord)
+        errors.add(:title, I18n.t(:invalid_characters))
+        return
+      end
+    end
+  end
+
   
   def new_version_required?
     return true if title_changed?

config/locales/en.yml

@@ -8,6 +8,7 @@ en:
   too_many_links: "has too many links"
   just_posted_that: "is too similar to what you recently posted"
   has_already_been_used: "has already been used"
+  invalid_characters: "contains invalid characters"
 
   activerecord:
     attributes:

spec/models/topic_spec.rb

@@ -1,3 +1,5 @@
+# encoding: UTF-8
+
 require 'spec_helper'
 
 describe Topic do
@@ -24,6 +26,18 @@ describe Topic do
 
   it { should rate_limit }
 
+  context 'topic title content' do
+
+    it "allows a regular title with a few ascii characters" do
+      Fabricate.build(:topic, title: "hello this is my cool topic! welcome: all;").should be_valid
+    end
+
+    it "doesn't allow non standard ascii" do
+      Fabricate.build(:topic, title: "Iñtërnâtiônàlizætiøn").should_not be_valid
+    end
+
+  end
+
 
   context 'topic title uniqueness' do