Fix #837 Chinese, Russian headers, thx finalnova

Author: lord

lib/unique_head.rb

@@ -1,17 +1,24 @@
 # Unique header generation
 require 'middleman-core/renderers/redcarpet'
+require 'digest'
 class UniqueHeadCounter < Middleman::Renderers::MiddlemanRedcarpetHTML
   def initialize
     super
     @head_count = {}
   end
   def header(text, header_level)
     friendly_text = text.gsub(/<[^<]+>/,"").parameterize
+    if friendly_text.strip.length == 0
+      # Looks like parameterize removed the whole thing! It removes many unicode
+      # characters like Chinese and Russian. To get a unique URL, let's just
+      # URI escape the whole header
+      friendly_text = Digest::SHA1.hexdigest(text)[0,10]
+    end
     @head_count[friendly_text] ||= 0
     @head_count[friendly_text] += 1
     if @head_count[friendly_text] > 1
       friendly_text += "-#{@head_count[friendly_text]}"
     end
     return "<h#{header_level} id='#{friendly_text}'>#{text}</h#{header_level}>"
   end
-end
+end