Content-Disposition header problems

Hello,

after uploading a screenshort as rather small png-File and using it embedded as <img> (which doesn't trigger the problem), I figured it would be nice to have a full size version opening up when clicking on the thumbnail. So I uploaded a full size version as well.

But when I get the pop-up (simple target="_blank" link, nothing special), I'm presented with the choice to view (with the browser) or save the png file, as if this was some kind of attachment. Looking into the http-headers I found the Content-disposition header set to "attachment" (function imce_file_download in imce.module), which is wrong IMO. Removing the Content-Disposition header fixes the problem, which btw shows up both in Opera and in Firefox, haven't found time to test it in IE6/7, but I guess it's the same there.

Test page (which still sends the Content-Disposition header) is at http://linux.spiney.org/debian_linux_maemo_nokia_770_winzig_port, click the screenshot to get the view/save dialog.

Trivial patch is attached, but I I'd like to know why you put the Content-Disposition header into the reply in the first place, is there any specific reason for this? I can understand it for non-graphics files (hence I left the second Content-Disposition header in place, but for gif/jpg/png it's natural to let the browser do the work, isn't it?

Kind regards
Wolfgang Karall