Proxy issues when using a proxy PAC file returning no port number

FULL PRODUCT VERSION :
java version "1.8.0_51"
Java(TM) SE Runtime Environment (build 1.8.0_51-b16)
Java HotSpot(TM) Client VM (build 25.51-b03, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 6.1.7601]

EXTRA RELEVANT SYSTEM CONFIGURATION :
Internet access only via proxy server.
Internet Explorer 11.
Configured with auto proxy (proxy PAC)
Java Control Panel network settings configured to use browser settings.
Webstart application hosted on a local server (not internet), i.e. does not require proxy access.

A DESCRIPTION OF THE PROBLEM :
Problems occur when a Java webstart program or Applet accesses the internet via a proxy server. The proxy server is determined from a proxy PAC file which does not return a port number in the URL.

This is OK when browsing using Internet Explorer, but java fails to download the files/jars. It works OK if the proxy PAC is updated to return a port number in the URL.

Note: This fix should also resolve incident https://bugs.openjdk.java.net/browse/JDK-8132011

REGRESSION. Last worked in version 6u45

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Using a PC which has no internet access other than via a proxy server.
Using the Java Control Panel Network screen, configure a proxy PAC file (can use local file e.g. file://c:\temp\proxypac.txt) with content such as the following:
{code}
var normal="PROXY proxy.server.name.here.com";
function FindProxyForURL(url, host) {
    return normal;
}
{code}

Configure your browser to use the proxy pac file.
Navigate to a url which downloads an applet e.g. http://java.com/verify
or a webstart application e.g. https://docs.oracle.com/javase/tutorial/deployment/webstart/examplesIndex.html

These will fail to download the jars or validate the security certificate

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The applet is started and works OK.
The webstart application is downlaoded and works OK.
ACTUAL -
Applet fails to download, and a timeout occurs
Webstart application fails with an error "Failed to validate certificate"

REPRODUCIBILITY :
This bug can be reproduced always.

CUSTOMER SUBMITTED WORKAROUND :
Change the Network Settings in Java Control Panel, to use a proxy server directly (i.e. not use the browser settings, nor provide an automatic proxy script.)