Support non-english topic titles

app/assets/javascripts/discourse/models/topic.js.coffee

@@ -25,7 +25,9 @@ Discourse.Topic = Discourse.Model.extend Discourse.Presence,
   ).property('categoryName', 'categories')
 
   url: (->
-    "/t/#{@get('slug')}/#{@get('id')}"
+    slug = @get('slug')
+    slug = "topic" if slug.isBlank()
+    "/t/#{slug}/#{@get('id')}"
   ).property('id', 'slug')
 
   # Helper to build a Url with a post number

app/models/topic.rb

@@ -129,7 +129,6 @@ class Topic < ActiveRecord::Base
     end
   end
 
-
   def new_version_required?
     return true if title_changed?
     return true if category_id_changed?
@@ -497,7 +496,9 @@ class Topic < ActiveRecord::Base
   end
 
   def slug
-    Slug.for(title)
+    result = Slug.for(title)
+    return "topic" if result.blank?
+    result
   end
 
   def last_post_url

spec/controllers/list_controller_spec.rb

@@ -37,7 +37,7 @@ describe ListController do
 
       context 'with a link that includes an id' do
         before do
-          xhr :get, :category, category: "#{category.slug}-#{category.id}"
+          xhr :get, :category, category: "#{category.id}-#{category.slug}"
         end
 
         it { should respond_with(:success) }

spec/models/topic_spec.rb

@@ -49,6 +49,22 @@ describe Topic do
 
   end
 
+  context 'slug' do
+
+    let(:title) { "hello world topic" }
+    let(:slug) { "hello-world-slug" }
+
+    it "returns a Slug for a title" do
+      Slug.expects(:for).with(title).returns(slug)
+      Fabricate.build(:topic, title: title).slug.should == slug
+    end
+
+    it "returns 'topic' when the slug is empty (say, non-english chars)" do
+      Slug.expects(:for).with(title).returns("")
+      Fabricate.build(:topic, title: title).slug.should == "topic"
+    end
+
+  end
 
   context 'topic title uniqueness' do