[PATCH] AppGenerator fails when using --pretend option

I'm not sure if this is definitely an issue with rails or a recent change to thor, but I noticed that when running rails new myapp --pretend, I received an error:

ree(1.8.7@rails3rc) blakey:~ $ rails new myapp --pretend
      create  
/Users/steve/.rvm/rubies/ree-1.8.7-2010.01/lib/ruby/1.8/fileutils.rb:121:in `chdir': No such file or directory - /Users/steve/myapp (Errno::ENOENT)
    from /Users/steve/.rvm/rubies/ree-1.8.7-2010.01/lib/ruby/1.8/fileutils.rb:121:in `cd'
    from /Users/steve/.rvm/gems/ree-1.8.7-2010.01@rails3rc/gems/railties-3.0.0.rc/lib/rails/generators/rails/app/app_generator.rb:219:in `create_root'
    from /Users/steve/.rvm/gems/ree-1.8.7-2010.01@rails3rc/gems/thor-0.14.0/lib/thor/task.rb:22:in `send'
    from /Users/steve/.rvm/gems/ree-1.8.7-2010.01@rails3rc/gems/thor-0.14.0/lib/thor/task.rb:22:in `run'
    from /Users/steve/.rvm/gems/ree-1.8.7-2010.01@rails3rc/gems/thor-0.14.0/lib/thor/invocation.rb:118:in `invoke_task'
    from /Users/steve/.rvm/gems/ree-1.8.7-2010.01@rails3rc/gems/thor-0.14.0/lib/thor/invocation.rb:124:in `invoke_all'
    from /Users/steve/.rvm/gems/ree-1.8.7-2010.01@rails3rc/gems/thor-0.14.0/lib/thor/shell.rb:14:in `map'
    from /Users/steve/.rvm/gems/ree-1.8.7-2010.01@rails3rc/gems/thor-0.14.0/lib/thor/core_ext/ordered_hash.rb:73:in `each'
    from /Users/steve/.rvm/gems/ree-1.8.7-2010.01@rails3rc/gems/thor-0.14.0/lib/thor/invocation.rb:124:in `map'
    from /Users/steve/.rvm/gems/ree-1.8.7-2010.01@rails3rc/gems/thor-0.14.0/lib/thor/invocation.rb:124:in `invoke_all'
    from /Users/steve/.rvm/gems/ree-1.8.7-2010.01@rails3rc/gems/thor-0.14.0/lib/thor/group.rb:226:in `dispatch'
    from /Users/steve/.rvm/gems/ree-1.8.7-2010.01@rails3rc/gems/thor-0.14.0/lib/thor/base.rb:389:in `start'
    from /Users/steve/.rvm/gems/ree-1.8.7-2010.01@rails3rc/gems/railties-3.0.0.rc/lib/rails/commands/application.rb:18
    from /Users/steve/.rvm/rubies/ree-1.8.7-2010.01/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
    from /Users/steve/.rvm/rubies/ree-1.8.7-2010.01/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
    from /Users/steve/.rvm/gems/ree-1.8.7-2010.01@rails3rc/gems/railties-3.0.0.rc/lib/rails/cli.rb:12
    from /Users/steve/.rvm/rubies/ree-1.8.7-2010.01/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
    from /Users/steve/.rvm/rubies/ree-1.8.7-2010.01/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
    from /Users/steve/.rvm/gems/ree-1.8.7-2010.01@rails3rc/gems/rails-3.0.0.rc/bin/rails:4
    from /Users/steve/.rvm/gems/ree-1.8.7-2010.01@rails3rc/bin/rails:19:in `load'
    from /Users/steve/.rvm/gems/ree-1.8.7-2010.01@rails3rc/bin/rails:19

I've fixed the app generator so that it works as expected now.