Elgg/Elgg — pull request #361 by skamolov (2012-08-08 11:44:39+00:00)
Title: Download button should work as downloading on pc and not as preview.

when user try to download some of the png files (for ex.) it automatically opens in browser.
I suggest to add a specific header inside file /mod/file/pages/file/download.php:

header("Content-type: application/force-download");

It allow to display a dialog for saving file on users pc