NO_PROXY auto-detection without http_configuration gem

persistent.rb.diff

--- bundler-1.1.5/lib/bundler/vendor/net/http/persistent.rb.orig        2012-08-17 15:02:50.000000000 +0900
+++ bundler-1.1.5/lib/bundler/vendor/net/http/persistent.rb     2012-08-17 15:01:17.000000000 +0900
@@ -163,6 +163,11 @@
                  else raise ArgumentError, 'proxy must be :ENV or a URI::HTTP'
                  end

+    @no_proxy = []
+    if proxy == :ENV
+      @no_proxy = (ENV['NO_PROXY'] || ENV['no_proxy'] || 'localhost, 127.0.0.1').split(/\s*,\s*/)
+    end
+
     if @proxy_uri then
       @proxy_args = [
         @proxy_uri.host,
@@ -205,7 +210,7 @@
     net_http_args = [uri.host, uri.port]
     connection_id = net_http_args.join ':'

-    if @proxy_uri then
+    if @proxy_uri && out_of_noproxy?(uri) then
       connection_id << @proxy_connection_id
       net_http_args.concat @proxy_args
     end
@@ -231,6 +236,13 @@
     raise Error, "host down: #{connection.address}:#{connection.port}"
   end

+  def out_of_noproxy?(uri)
+    @no_proxy.each do |host_addr|
+      return false if uri.host.match(Regexp.quote(host_addr) + '$')
+    end
+    return true
+  end
+
   ##
   # Returns an error message containing the number of requests performed on
   # this connection