Bug #16109 Updated: zlib.output_compression and generated pictures

ID: 16109 Updated by: sr@php.net Reported By: pguillot@paanjaru.com -Status: Open +Status: Feedback Bug Type: Zlib Related Operating System: linux PHP Version: 4.1.2 New Comment: Are you sure mod_gzip compresses the pictures? Try to explicitly configure mod_gzip to compress images and please give us feedback if they work with your Netscape. I did a short test here and they also didn't work, so it seems really a Netscape problem. Other test: Does it work if you switch of zlib.output_compression and instead compress the page via mod_gzip? Previous Comments: ------------------------------------------------------------------------ [2002-05-29 03:54:17] php@fatalfx.com Here's a short reproducing example script. Since the two pictures on the php info page are "generated" (inline) the script is very short: <?php phpinfo(); ?> Make sure your zlib.output_compression = On and you use Netscape Communicator 4.79 (Maybe the "bug" is in other Netscape version too but in 4.79 it is for sure). Roger ------------------------------------------------------------------------ [2002-05-28 15:47:52] pguillot@paanjaru.com Welcome to the twilight zone ... After a question from Roger Wetzel, I made a few more tests. It seems the problem is on the netscape side : I tested Netscape 7.0PR1 and the pictures are ok even with zlib.output_compression enabled ... Using my old Netscape 4.77 the problem remains even if the apache httpd.conf contains a KeepAlive set to Off or MaxRequestsPerChild set to 1 ... So it's should not be a keep-alive problem. What still is in question is that when using mod_gzip, the problem doesn't occur. So there is a workaround , either disable zlib.output_compression or use a decent mozilla/netscape. Patrick ------------------------------------------------------------------------ [2002-05-28 10:23:51] php@fatalfx.com When I look at http://www.php.net/manual/en/function.ini-set.php it says that the value can be set anywhere (PHP_INI_ALL). Yes, that true what it has no effect. The master value on my computer is "on" and when I set it "off" at the beginning of my script it has no effect (even if phpinfo() tells the local value is "off"). So all pictures I read out from my database are not shown (broken image) in Netscape. Why can't I switch it "off" in a particular script? Is it a problem with the headers (Content-Encoding)? I really would like to have it switched "on" to keep the data transfer as low as possible. But if my pictures aren't shown in Netscape it's of no use. Actually, where is the bug? In the zlib? In Netscape? Roger ------------------------------------------------------------------------ [2002-04-03 15:03:30] pguillot@paanjaru.com Thanks a lot Sniper ! After a little digging, the only bug report 'related' to the problem discussed here seems bug #10905 which was closed because of no feed back. The strange point about what is happening is that pictures .png or .jpeg are already compressed, due to the format itself ... Also, if I use apache's mod_gzip to compress again the pictures, it works, and other non script generated pictures are ok too. Sounds weird. ;-) Patrick ------------------------------------------------------------------------ [2002-04-03 08:47:40] sniper@php.net If you can't find the number for the other bug report, leave the report open.. ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at http://bugs.php.net/16109 -- Edit this bug report at http://bugs.php.net/?id=16109&edit=1