RT double-gzipping attachments

I’ve got a weird problem with my RT installtion, occurring on both my
3.8.1 test install and 3.6.5 production installation.

Normally if I attach a file to a ticket via the web interface as
Correspondence, then download the file from the server, I get the same
file back. However, if I do this with a gzip’ed file, I get a
double-gzip’ed file back.

Example session:

<>:~$ echo $( K=100;while [ “${K}” != “0” ]; do K=$(( ${K} - 1 )); echo
-n "DATA "; done; echo “” ) > file1.txt
<>:~$ cksum file1.txt
2112801529 500 file1.txt
<>:~$ gzip file1.txt
<>:~$ cksum file1.txt.gz
3313752743 41 file1.txt.gz
------ Upload file to RT ticket, then download file again from RT
ticket
<>:~$ cksum file1.txt.gz
3957064899 61 file1.txt.gz
<>:~$ gunzip file1.txt.gz
<>:~$ cksum file1.txt
3313752743 41 file1.txt
<>:~$ file file1.txt
file1.txt: gzip compressed data, was “file1.txt”, from Unix, last
modified: Thu Dec 18 16:09:43 2008
<>:~$ mv file1.txt file1.txt.gz
<>:~$ gunzip file1.txt.gz
<>:~$ cksum file1.txt
2112801529 500 file1.txt

I have looked in the RT source and can’t find a place where gzip is
called, nor can I find something akin to this in my Apache
configuration. Does anyone have an idea where I can look for a solution
to this?

RT: 3.6.5
CentOS 5 i386
Apache: httpd-2.2.3-11.el5_1.centos.3
MySQL: mysql-5.0.45-7.el5
Perl: perl-5.8.8-15.el5_2.1

Thanks in advance :slight_smile:

Braam van Heerden

Hello Braam!

I can’t reproduce the problem in 3.8.1. I would check the webserver
configuration (mod_deflate?), or maybe a ‘special’ browser plugin.

regards!

svenOn Fr, 2008-12-19 at 09:47 +0200, Braam van Heerden wrote:

I’ve got a weird problem with my RT installtion, occurring on both my
3.8.1 test install and 3.6.5 production installation.

Normally if I attach a file to a ticket via the web interface as
Correspondence, then download the file from the server, I get the same
file back. However, if I do this with a gzip’ed file, I get a
double-gzip’ed file back.

Example session:


<>:~$ echo $( K=100;while [ “${K}” != “0” ]; do K=$(( ${K} - 1 )); echo
-n "DATA "; done; echo “” ) > file1.txt
<>:~$ cksum file1.txt
2112801529 500 file1.txt
<>:~$ gzip file1.txt
<>:~$ cksum file1.txt.gz
3313752743 41 file1.txt.gz
------ Upload file to RT ticket, then download file again from RT
ticket
<>:~$ cksum file1.txt.gz
3957064899 61 file1.txt.gz
<>:~$ gunzip file1.txt.gz
<>:~$ cksum file1.txt
3313752743 41 file1.txt
<>:~$ file file1.txt
file1.txt: gzip compressed data, was “file1.txt”, from Unix, last
modified: Thu Dec 18 16:09:43 2008
<>:~$ mv file1.txt file1.txt.gz
<>:~$ gunzip file1.txt.gz
<>:~$ cksum file1.txt
2112801529 500 file1.txt


I have looked in the RT source and can’t find a place where gzip is
called, nor can I find something akin to this in my Apache
configuration. Does anyone have an idea where I can look for a solution
to this?

RT: 3.6.5
CentOS 5 i386
Apache: httpd-2.2.3-11.el5_1.centos.3
MySQL: mysql-5.0.45-7.el5
Perl: perl-5.8.8-15.el5_2.1

Thanks in advance :slight_smile:

Braam van Heerden


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Sven,

You were indeed correct. The culprit was mod_deflate, though it was
configured only in a different vhost. Seems once it’s loaded it affects
everyone.

Thanks a lot for your help in this.

  • BraamFrom: Sven Sternberger [mailto:sven.sternberger@desy.de]
    Sent: 19 December 2008 15:10 PM
    To: rt-users
    Subject: Re: [rt-users] RT double-gzipping attachments

Hello Braam!

I can’t reproduce the problem in 3.8.1. I would check the webserver
configuration (mod_deflate?), or maybe a ‘special’ browser plugin.

regards!

sven