User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:26.0) Gecko/20100101 Firefox/26.0 (Beta/Release) Build ID: 20131205075310 Steps to reproduce: I was uploading a file I downloaded in my phone to an iPad running VLC local uploader. The file is a movie so it's like 600MB. I used the upload form, selected the file I wanted to upload. Actual results: I got the wait or quit dialog 2 or 3 times. After like a minute or so the browser came back and the upload started. Expected results: The browser should come back immediatly and start uploading the selected file. When cleaning up the movies downloaded I checked that the storage was still missing a chunk of space, so checking the settings/storage on android, Firefox came first with a cache of 1.5 GB, so I think what happened was that the file was copied first to a firefox internal app directory before uploading, that is why it was waiting. Firefox should have used the file directly to upload without duplicating it.

See also Bug 942611, which is about cleanup. Almost a dupe.