(PUP-391) Fix Rdoc 4+ specs on Windows Ruby 2 x64

 - When calling the document method on RDoc and the root option has not
   been specified, RDoc will provide a default in the options class:
   @root = Pathname(Dir.pwd).  NOTE: This does not affect RDoc 3.9.5
   that ships with Ruby 1.9.3 on Windows, only RDoc 4.0.0+ that ships
   with Ruby 2.0.0+ on Windows.
 - The win32-dir monkey patches the Dir.pwd method, and instead of
   using / separators like the rest of Ruby, it uses \ as a path
   separator.
 - RDoc uses Pathname, specifically the relative_path_from method
   which expects / separators, and gets confused with \.  Therefore,
   provide a workaround to ensure that Windows uses the appropriate
   / in paths.

Author: Iristyle

lib/puppet/util/rdoc.rb

@@ -37,6 +37,13 @@ def rdoc(outputdir, files, charset = nil)
       options << "--force-update"
     end
     options += [ "--charset", charset] if charset
+    # Rdoc root default is Dir.pwd, but the win32-dir gem monkey patchs Dir.pwd
+    # replacing Ruby's normal / with \.  When RDoc generates relative paths it
+    # uses relative_path_from that will generate errors when the slashes don't
+    # properly match.  This is a workaround for that issue.
+    if Puppet.features.microsoft_windows? && RDoc::VERSION !~ /^[0-3]\./
+      options += [ "--root", Dir.pwd.gsub(/\\/, '/')]
+    end
     options += files
 
     # launch the documentation process