Well, my guess we need to modify our "bad" header. We are getting our "bad" header when the initial request is redirected to a some "dummy" location, such locations are pretty common in my case (.../sorry... ; .../Error/...; etc) so we just need to make initial request right from the "bad", for example this is a bad request:

http://www.google.co.uk/sorry/?continue=http://www.google.co.uk/search%3Fq%3Djust+an+example

We can detect it by ../sorry/.. in the middle, and this link will lead us straight to the captcha request page, this is not what we need, we need just:

http://www.google.co.uk/search%3Fq%3Djust+an+example

So we are extracting from the "Location" Header "bad" location header and replacing it with a "good" one. Although I have not much of experince, I tried to write a code, atleast I'd like to belive that it's a code, and not just a mess :). Also I'm stuck with one thing, I can't figure out how to pass additional parameters to a HTTP::Proxy if new() method already used.

#!/usr/bin/perl

use strict;
use warnings;
use HTTP::Proxy qw( :log );
use HTTP::Proxy::HeaderFilter::simple;
use  LWP::UserAgent;                                                  
+                                                  
my $ua = LWP::UserAgent->new();                                       
+                                                                     
+                 
$ua->proxy(['http'],'http://127.0.0.1:29999');                        
+                                                                     
+                     
$ua->timeout(10);                                                     
+                                                                     
+                              
$ua->agent('Mozilla/5.0 (Windows NT 6.1) AppleWebKit/534.24 (KHTML, li
+ke Gecko) Chrome/11.0.696.60 Safari/534.24');

open ( LOGFILE, ">>", "/var/log/repeater.log");    # ##<----- 2)

my $proxy = HTTP::Proxy->new(
                port => '38374',
                agent => $ua,
                logfh => <LOGFILE>,
                );
#HTTP::Proxy->new(@ARGV); ###  <--3)
$proxy->logmask( ALL );


$proxy->push_filter(
     host     => 'google.com', # only apply to this domain

     response => HTTP::Proxy::HeaderFilter::simple->new( sub { my ( $s
+elf, $headers, $response ) = @_;
         # skip non redirects
           return if $response->code !~ /^3/;
         # pick up location
            my $location = $headers->header('Location');
         # find bad redirections
            if ( $location =~ m{google.com/sorry.*} ) {

        # change the redirect
            my $new_location = $location ;
            $new_location =~ s/.*(\/sorry\/\?continue=.*)/$1/gx ;
            $new_location =~ s/\/sorry\/\?continue=//;

            $headers->header( Location => $new_location );
        # print some logging information
            $self->proxy->log( ALL,

                          LOCATION => "$location => $new_location"  );
                }
        }
    )
);
$proxy->start;
[download]

P.S. Clients are operating through the parent proxies so it makes sense to try to repeat request. Thanks in advance, Sergey.