Prevent _includes dir from being a symlink.

History.txt

@@ -9,6 +9,7 @@
   * Bug Fixes
     * Fixed filename basename generation (#208)
     * Set mode to UTF8 on Sequel connections (#237)
+    * Prevent _includes dir from being a symlink
 
 == 0.7.0 / 2010-08-24
   * Minor Enhancements

lib/jekyll/tags/include.rb

@@ -7,11 +7,17 @@ module Jekyll
     end
 
     def render(context)
+      includes_dir = File.join(context.registers[:site].source, '_includes')
+
+      if File.symlink?(includes_dir)
+        return "Includes directory '#{includes_dir}' cannot be a symlink"
+      end
+
       if @file !~ /^[a-zA-Z0-9_\/\.-]+$/ || @file =~ /\.\// || @file =~ /\/\./
         return "Include file '#{@file}' contains invalid characters or sequences"
       end
 
-      Dir.chdir(File.join(context.registers[:site].source, '_includes')) do
+      Dir.chdir(includes_dir) do
         choices = Dir['**/*'].reject { |x| File.symlink?(x) }
         if choices.include?(@file)
           source = File.read(@file)