[Affected versions]: - Latest Nightly - Latest Aurora - 50.0b9 build1 (20161020152750) - 49.0.1 (20160922113459) [Affected platforms]: - Windows 10 x64/ x86 - Mac OS X 10.10.5 - Ubuntu 14.04 x86 [Steps to reproduce]: 1. Launch Firefox 2. Download a large file (ex: https://www.ubuntu.com/download/desktop/thank-you?country=RO&version=16.04.1&architecture=amd64) 3. Leave the progress download to advance until near the end (it's better reproducible this way) 4. Open the Download Panel 5. Right click on downloaded item and toggle between Pause and Resume multiple times [Expected result]: - The Pause / Resume options are available as soon as one of the options is toggled - Each of Pause / Resume options are properly applied to the download item [Actual result]: - As the download progress advances, the Pause / Resume options are slowly triggered (see the screencast https://dl.dropboxusercontent.com/u/109148197/Download%20panel/Large%20file%20download.gif) [Regression range]: - This is also reproducible on 49.0.1 (20160922113459) - I will continue investigating this as soon as possible
I was able to reproduce this on old builds as well, going back to 30.0 RC so I think it's safe to say this is NOT a recent regression.
[Regression range]: - Last good revision: bc8c1eb0f2ba (2013-11-11) - First bad revision: 581d180a37f3 (2013-11-12) - Pushlog: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=bc8c1eb0f2ba&tochange=581d180a37f3
Forgot to mention: a possible regressor is bug 895476.
This is likely something that we'd want to investigate, although it's a minor issue as far as I can tell, since pause and resume are not often used. If this is related to bug 895476, it means that there might be some extra network access we shouldn't do when pausing, or maybe we have slowness with the background file saver when using hashing functions.
Put it to CHE backlog since it's related to, but not caused by what our project is doing.