Fix BlahTeX/PNG

The BlahTeX/PNG code was busted by Revision 344.
Fixed now.
Ari better supply me with a test suite, so this doesn't happen again.

app/controllers/file_controller.rb

@@ -36,6 +36,10 @@ class FileController < ApplicationController
       end
     end
   end
+  
+  def blahtex_png
+    send_file(@web.blahtex_pngs_path + '/' + params['id'])
+  end
     
   def delete
     @file_name = params['id']

app/models/web.rb

@@ -125,6 +125,14 @@ class Web < ActiveRecord::Base
     end
   end
 
+  def blahtex_pngs_path
+    if default_web?
+      "#{RAILS_ROOT}/webs/files/pngs"
+    else
+      "#{RAILS_ROOT}/webs/#{self.address}/files/pngs"
+    end
+  end
+
   private
 
     # Returns an array of all the wiki words in any current revision

config/routes.rb

@@ -19,6 +19,7 @@ ActionController::Routing::Routes.draw do |map|
   connect_to_web map, ':web/remove_orphaned_pages', :controller => 'admin', :action => 'remove_orphaned_pages'
   connect_to_web map, ':web/remove_orphaned_pages_in_category', :controller => 'admin', :action => 'remove_orphaned_pages_in_category'
   connect_to_web map, ':web/file/delete/:id', :controller => 'file', :action => 'delete', :requirements => {:id => /[-._\w]+/}, :id => nil
+  connect_to_web map, ':web/files/pngs/:id', :controller => 'file', :action => 'blahtex_png', :requirements => {:id => /[-._\w]+/}, :id => nil
   connect_to_web map, ':web/files/:id', :controller => 'file', :action => 'file', :requirements => {:id => /[-._\w]+/}, :id => nil
   connect_to_web map, ':web/file_list/:sort_order', :controller => 'wiki', :action => 'file_list', :sort_order => nil
   connect_to_web map, ':web/import/:id', :controller => 'file', :action => 'import'