HOLD IT - I just found out exactly how to reproduce it. please read carefully.

the code is:
<?php
function ImageExists($url) {
  $r=@getimagesize($url);
  return $r[2]!=0;
}
echo ImageExists('http://domain/dir1/dir2/dir3/image.gif');
?>

make sure the path:
http://domain/dir1/dir2/dir3/
containts THREE directories after the domain (i.e. 6 forward-slashes total), and that the PATH physically EXISTS.

AND make sure that the file (in code 'image.gif') DOES NOT exist.

You can test against:
http://economads.com/libaware/_font/title/image.gif

This crashes on my server - running PHP 4.3.0 as CGI with IIS Win2000. 

Hope this helps.

I finally got around installing PHP to my windows (2k) machine and could reproduce this crash.

This is the error I get (as expected):
..function.getimagesize: failed to open stream: HTTP request failed! HTTP/1.1 404 Not Found in...

But it also popups that windows error about '..generated errors..blabla..'.

It happens only with longer urls it seems. The one in
above comment does not cause the crash for me.

Seems like some oddity with the streams stuff, assigning to Wez. :)

i only get the GPF crash, no messages.. i hope you reproduced the same bug. also since the script in the second comment does crash on my system. we'll see - just tell me when a dev version is ready.

Now I can not reproduce this anymore using the given location. (with latest snapshot)

Please try using this CVS snapshot:

  http://snaps.php.net/php4-STABLE-latest.tar.gz
 
For Windows:
 
  http://snaps.php.net/win32/php4-win32-STABLE-latest.zip

A number of fixes went into CVS last night; it is quite possible that this problem is fixed (we've had a good response so far).
Please try a stable snapshot.

ok i tried it (unzipped into a new dir and rebooted) and it still crashes, just with different hex addresses in the GPF message.

I doesn't crash for me anymore using this script:

<?php var_dump(getimagesize('http://economads.com/libaware/_font/title/image.gif')); ?>

Can you verify that this exact script causes the crash?
And if so, could you also test this on some other machine too?

that script you posted doesn't crash on my system either - but this one does:

function ImageExists($url) {
  $r=@getimagesize($url);
  return $r[2]!=0;
}
echo ImageExists('http://economads.com/libaware/_font/title/123456.gif');

it's funny, if the file name is 12345.gif it doesn't crash, but if it's 123456.gif than it does!

Are you using the latest CVS snapshot? (if not get it)

i downloaded the 4.3.x snapshot quite a few times, and i can try again - but do you mean i should try the 5.0.x snapshot?

I can't reproduce this problem either, under winxp.
Could you try the latest stable snapshot again?

If it crashes, please paste here the error message that you are seing, along with the date/time of the snapshot that you tried.

i have windows 2000 pro not XP.
it still crashes with the latest stable snapshot:
php4-win32-STABLE-200303201730.zip

the error message dialog can be found here:

http://ofek.com/ebimg/1.gif

ok, i just got a new machine, and installed Windows XP Pro this time with the latest stable php 4.3.1 - still crashing! this code won't run!

Make sure you try the snapshot and not 4.3.1?

I really can't reproduce it here.  It is possibly related to some other memory corruption elsewhere (another recently reported bug); I'm keeping this open for now, until we track down the problem with the other bug.

What extensions do you have loaded?
Can you put your phpinfo() output somewhere that we can see it online?

Please try using this CVS snapshot:

  http://snaps.php.net/php4-STABLE-latest.tar.gz
 
For Windows:
 
  http://snaps.php.net/win32/php4-win32-STABLE-latest.zip

I've just fixed a bug in fopen() of http:// urls; this will most likely fix your problem here.

Please try the *next* snapshot (the fix has only just gone into CVS).

Next STABLE Win32 snapshot in: 1 hour(s) and 28 minute(s)

downloaded the last snapshot, and it looks like it is fixed! thanks. is this fix going to be part of 4.3.2 and do you know when it's due out? 
thank you for your efforts.

The fix will be in 4.3.2 as well.