You ought to be able to get info on any download, even after they have completed. Plus I think sdwilsh doesn't have enough work to do.
I'm going to wait to work on this until Bug 382825 lands since there's a nice helper function that I can use (in that patch) to make this a really trivial fix.
Created attachment 267281 [details] [diff] [review] v1.0 whoops...forgot to attach this yesterday
Comment on attachment 267281 [details] [diff] [review] v1.0 It's probably a good thing that I didn't...this won't work anyway.
Created attachment 267288 [details] [diff] [review] v1.1 Now with no null dereferencing and a unit test!
Comment on attachment 267288 [details] [diff] [review] v1.1 This looks OK, but don't you also need to change the code at http://bonsai.mozilla.org/cvsblame.cgi?file=mozilla/toolkit/mozapps/downloads/content/downloadProperties.js&rev=1.5&mark=86#85 , which assumes that getDownload() throws for inactive downloads?
(In reply to comment #5) Yes, but I changed that with Bug 381927 since that whole page was completely wrong anyway. I planned on landing these both at the same time.
Comment on attachment 267288 [details] [diff] [review] v1.1 Fine, be that way!
Checking in toolkit/components/downloads/public/nsIDownloadManager.idl; new revision: 1.12; previous revision: 1.11 Checking in toolkit/components/downloads/src/nsDownloadManager.cpp; new revision: 1.85; previous revision: 1.84 Checking in toolkit/components/downloads/test/unit/test_download_manager.js; new revision: 1.13; previous revision: 1.12 Checking in toolkit/components/downloads/test/unit/test_download_manager_migration.js; new revision: 1.6; previous revision: 1.5