204604 - PAC: ret = FindProxyForURL(url, host); fails

Status: VERIFIED INVALID

(Core :: Networking, defect)

Description

[Donal Hunt]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.4b) Gecko/20030505
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.4b) Gecko/20030505

The network.proxy.autoconfig_url in the latest build release (and in past
releases) does not work.  Using manual proxy settings allows a user to connect
to the relevant proxy server.  Using the above preference results in no webpages
being loaded.

Reproducible: Always

Steps to Reproduce:
1.  change the preferences to use automatic configuration script.
2.  attempt to access external websites (local websites display ok)
Actual Results:  
no page loads - status page is still attempting to load the page but fails after
a minute or two.

Expected Results:  
should have connected to the proxy server specified in the proxy.pac file and
loaded the website.

proxy.pac file:

// DCU standard proxy autoconfiguration script.
//
// Tested on Netscape 4.x
//                       IE 4.x
//                       IE 5.x
//                       IE 6.x

var url;
var host;

function FindProxyForURL(url, host) {

                // So we get Netscape errors on no host rather than a Squid
                // error saying contact [e-mail].
                if (!isResolvable(host))
                        return "DIRECT";

        if (isPlainHostName(host) ||
                        isInNet(host, "136.206.0.0", "255.255.0.0") ) {
                return "DIRECT";
                } else {
                        // Order is important here - IE works right to left I'm told
                        // Netscape works left to right (ie: Direct has to be in
middle).
                        return "PROXY proxy2.dcu.ie:3128; PROXY
proxy.dcu.ie:3128; DIRECT; PROXY proxy.dcu.ie:3128; PROXY proxy2.dcu.ie:3128";
        }
}
ret = FindProxyForURL(url, host);

Comment 1

[benc]

Are you saying that all PAC is broken, or just your file?

Comment 2

[Donal Hunt]

the PAC file i included is definately broken (it works with IE and Netscape
4.x).  If you have another PAC file you want me to test let me know...

Comment 3

[oliver jehle]

have the same problem with w2000..... linux  1.4b works !!!

also all older releases of mozilla under windows and 
linux work with the same pac file...

Comment 4

[Donal Hunt]

OK - just installed mozilla 1.4b and the same problem still exists.  Further
investigation shows that mozilla doesn't like this line:

ret = FindProxyForURL(url, host);

I can't remember which broswer it is, but one of the browsers in common use
needs this line for the proxy.pac file to work.  There's argument here that says
that the other browser is broken, but as i'm going to give a guess it's IE, it's
going be hard to justify removing the line.  Can mozilla be told to ignore the
line? 

Comment 5

[oliver jehle]

there must be something different between the mozilla 1.4b windows and the linux
windows build and the pac handling .... 

when you try it with the linux version it works... 

i've the same pac file on my web server and looks working with all browsers,
except the 1.4b windows version... 

Comment 6

[Frank Visser]

I have exactly the same problem. I am using Windows NT 4. All versions of 
Mozilla until 1.3.1 work fine, but Mozilla 1.4b refuses to load the proxy PAC 
URL. The proxy.pac file contains the findProxyForUrl(url, host) command.

Comment 7

[Matthias Versen [:Matti]]

Have you installed mozilla in an EMPTY directory and not over an older build ?
(that means: uninstalling mozilla, delete all files in the mozilla application
directory [except the plugins subfolder] and reinstall mozilla)

Comment 8

[Donal Hunt]

Just installed mozilla 1.4b onto a win2k desktop that has never seen mozilla
before.  The only preference I changed was the "network.proxy.autoconfig_url"
one. The problem is re-produced on this brand new install.

I now have two PAC files.
proxy.pac that includes the line "ret = FindProxyForURL(url, host);".
mozilla.pac that doesn't include "ret = FindProxyForURL(url, host);".

mozilla.pac works on both my PC and the one above.  proxy.pac works on neither.

Comment 9

[Darin Fisher]

i don't think it makes any sense to be calling FindProxyForURL in the body of
your PAC file.  this bug seems invalid to me.  the browser will call your
FindProxyForURL function...

marking INVALID

Comment 10

[oliver jehle]

but it looks like a bug !!! why the same pack files works with 1.4b linux and
not with 1.4b windows ????? 

all other browsers can use the pac file, only the windows 1.4b has problems...

Comment 11

[benc]

Maybe if you could explain the reasoning for this line, we could discuss this
further.

PAC has a specification:

http://wp.netscape.com/eng/mozilla/2.0/relnotes/demo/proxy-live.html

My javascript is basically limited to supporting PAC, but as I understand it,
your file contains just the script for your FindProxyForURL. The browser calls
that function via the line you say doesn't work.

Here's the top paragraph:

The proxy autoconfig file is written in JavaScript. The file must define the
function:

        function FindProxyForURL(url, host)
        {
            ...
        }

which will be called by the Navigator in the following way for every URL that is
retrieved by it:

        ret = FindProxyForURL(url, host);

Comment 12

[oliver jehle]

i'm german speaking, so my english is sometime not understandable :-( sorry..

but i've this problem only on windows platforms with release 1.4b... with the
linux build it works.... 

i use the same pack file for all browser in our office.. all (IE,Netscape 4.X,
Mozilla 1.3*, Mozilla 1.4b/linux) work... but only the windows 1.4b beta not !!!!

please make a short test with the windows and the linux version and you will see
the problem.... 

Comment 13

[Darin Fisher]

hmm.. i tried this PAC file under win2k and it actually works for me.  i tested
the 20030512 mozilla trunk.  i'm curious... how did you install mozilla 1.4
beta?  did you uninstall 1.3 first?

Comment 14

[oliver jehle]

i've done a complete uninstall and delete the folder of the old mozilla
installation... then install new, it looks working.. but i've to verify it on
the other workstations... 

Comment 15

[Donal Hunt]

With regard to Darin Fisher's comment - it doesn't make any sense to be calling
FindProxyForURL in the body of the PAC file.  However, at least one popular
browser out there (I believe it's one of the versions of Internet Explorer) has
broken javascript support and requires the line to be present.

I can't confirm whether DCU's proxy.pac (the one we want to use - which includes
the line)) works for Mozilla 1.4b on Linux, but I'll check it out later today.

Also I've comfirmed the bug on a second workstation (comment #8).

Comment 16

[oliver jehle]

for me.. its fixed...  after deleting the old installation on windows and
reinstall, it works..

for people having trouble with pac.. my pac files looks 1:1 as following
sample..  it works with all browser used here... ie, netscape, mozilla..
stored in dos format... on the unix server, crlf ending lines

---------- sample.pac --------------
function FindProxyForURL(url, host)
    {
        if ( shExpMatch(url,"*localhost*") ||
             shExpMatch(url,"*127.0.0.1*") ||
             shExpMatch(url, "*somehost*")
             )
            return "DIRECT";
        else
            return "PROXY 172.16.1.1:3128;";
    }

Comment 17

[Darin Fisher]

ok, please ignore my comments about FindProxyForURL being called in the body of
the PAC file.  that should not matter to mozilla.  it was just my own confusion
about how PAC works that got in the way of realizing that this is just a
duplicate of the recent flurry of bugs about having to completely uninstall the
old version of mozilla before upgrading to 1.4.  reopening to mark as duplicate.

Comment 18

[Darin Fisher]

*** This bug has been marked as a duplicate of 205514 ***

Comment 19

[Darin Fisher]

reopening... jumped the gun it seems.  comment #8 invalidates the duplicate
resolution.

Comment 20

[Darin Fisher]

frank and oliver are experiencing bug 205514, but the bug reported by donal is
still unresolved.  donal: can you do me a favor and capture a HTTP log using the
steps described here:

  http://mozilla.org/projects/netlib/http/http-debugging.html

if you could attach the resulting log file to this bug report or email it to me
directly that would be most helpful.  thanks!

Comment 21

[Donal Hunt]

Attachment: Log file for mozilla as requested.

Thanks for re-opening the call.  The attachment should be online now.

As an aside, we've decided to remove the line on one of our production boxes to
see if anyone screams.	If no-one screams, it may be worth closing the call and
putting a note in the proxy documentation saying "if you have this line in your
proxy.pac file, remove it or mozilla won't work!!". ;-)

Comment 22

[Darin Fisher]

donal:

ok, thanks for the log file.  unfortunately, the only thing it tells me is that
your PAC file is not loaded.  i figured as much, but i just wanted to make sure.
 can you please upload the bad PAC file as an attachment to this bug report. 
maybe put it into a zip archive first before uploading.  that way i can unzip
and see the exact format of your PAC file with line endings preserved, etc.  thx! 

Comment 23

[Donal Hunt]

Attachment: proxy.pac file that fails to work in mozilla 1.4b

As requested, the PAC file that fails to load in mozilla 1.4b

Comment 24

[Gerhard Hossinger]

I experienced also a problem with the proxy.PAC file which my company 
uses also for load balancing.
Some links worked while others got the error message 
  "The proxy server you have configured could not be found. 
   Please check your proxy settings and try again".

When I tried the proxies manually, I found that one proxy server did not work.
Wen examining the proxy.pac file I saw that the load-balancing is done by a 
hash of the URL which then is used to decide whether to use proxy in the 
order as returned from FindProxyForURL() = "proxy1; proxy2" or "proxy2; proxy1" 

Therefore I believe that Mozilla does not try ALL proxies in the list 
returned by the function FindProxyForURL(url, host). 
I guess it starts from the beginning, but does not continue correctly with 
the next proxy server URL.

Example from FindProxyForURL(url, host) from our proxy.PAC ...
----------------------------------------------------
var n = URLhash2(url) % 2;

if (n < 1)
   return "PROXY ext-proxy1.siemens.se:8080; PROXY ext-proxy2.siemens.se:8080; ";
if (n < 2)
   return "PROXY ext-proxy2.siemens.se:8080; PROXY ext-proxy1.siemens.se:8080; ";
----------------------------------------------------

I am using Windows NT 4 + Mozilla 1.3

My collegue using WinXP and IE6 never felt any problems because of the failing 
proxy server because IE just went on to the next working proxy server.

Comment 25

[Donal Hunt]

A quick update as I haven't touched the bug in nearly a year!

As mentioned in comment #21, we removed the "ret = FindProxyForURL(url, host);"
line from the proxy.pac file and no one has screamed to date.

I think this bug can be closed as a result.

Comment 26

[benc]

VERIFIED/INVALID:
We aren't going to support this.

We load the PAC into a larger pile of Javascript code, maybe some errors show up
in console, if you want to figure out what is going on.