Big (more than ~1.8mb) attachments are failing to download to browser

[egor]

Steps to reproduce:

1. Open a mail in roundcube with 4mb attachment
2. Click on the attachment
3. The attachment is downloading

Results:

1. The size of the downloading file is not known to the browser
2. The download speed degrades until the download reaches about 1.6mb
3. At about 1.6mb downloading stops, server side closes connection

Expected results:

1. Content-length is supplied so that the browser and the user can be sure about the download consistency
2. Download speed is constant
3. Attach downloads fully.

Tested on:

1. The latest roundcube from svn
2. Different internet connections (all broadband, all direct, no proxy)
3. Different browsers
4. Different messages
5. Server: Linux, Apache 2.0.55, PHP 5.2.0

Please let me know if you need further input or repeatable test case.

[mankytongue]

I was also having this problem, getting partially downloaded images and so on.

I looked into the download-attachment code and tweaked it a bit. The modifications I made work well in my situation, the size of the file is reported to the browser and the downloads are complete (and also faster but that may just be psychological, my code shouldn't have any effect on that).

The script requires the use of a tmpfile, so there might be security implications if the files contain sensitive information. The web server (or owner of script process) needs write access to /tmp, but any path will do, even the 'temp' directory in the roundcube root.

I've attached the patch, which I wrote and applied against [ff52bee1].

[egor]

Thank you very much!

[mankytongue]

Request for modification/adaptation of the patch and perhaps to be included in the trunk.

[tomekp]

try

ini_set('zlib.output_compression', false);

[till]

I can't reproduce this, my zlib.output_compression is also off.

I added it to check.php and to .htaccess in [342db9d0].

The rest ist postponed to 0.1.1.

[alec]

Added Content-Length (from $part->size) in [2c6fa933].

[thomasb]

Fix of [2c6fa933] did not work as expected. We now disabled time limit for large downloads in [0ced2b9a] which will hopefully fix this isssue.