KB43596 - How is the proxy logic merged with a client-side proxy URL in the browser and one configured in the VPN connection profile?

This article provides details on how the proxy configuration for an instantproxy.pac file gets merged to a VPN tunneling profile.

The PCS device is configured with a proxy.pac URL in the VPN connection profile and the client PC has a different proxy.pac URL configured in the browser.  What is the expected result of the proxy.pac file when these two proxy configurations are merged?  

The client and server proxy.pac files are merged into one file called "instantproxy.pac" which then gets saved to the browser during the VPN session.

If Split Tunneling is enabled then the merged pac file will contain rules so that the server-side pac file is applied to the tunneled traffic and the rules in the client-side pac file are applied for the traffic that needs to bypass the tunnel.  The instantproxy.pac file will look something like this:
   
           else if (isInNet(host, "split tunnel include routes"))  à this condition is based on split tunneling include routes
    {
        return FindServerProxy(url, host);
   }
   else {
        return FindClientProxy(url, host);
   }
}
 
If Split Tunneling is disabled and all traffic is being tunneled then the client-side PAC file is not used.  In this case, the instantproxy.pac file stored in the browser for the VPN session will be formatted as follows:  {
   content of server side pac file
}           } else
{
return FindServerProxy(url, host);
}
}