If a download started by DownloadManager::startDownload() is cancelled before DownloadManager::willDecidePendingDownloadDestination() is called, DownloadManager::cancelDownload() does nothing, because the Download hasn't been created yet and m_downloadsWaitingForDestination map doesn't contain the download ID, and the PendingDownload is never removed from the m_pendingDownloads map.
Created attachment 291821 [details] Patch
Created attachment 291823 [details] Fix debug build with network session disabled. So, Mac EWS debug doesn't have network session enabled?
(In reply to comment #2) > Created attachment 291823 [details] > Fix debug build with network session disabled. > > So, Mac EWS debug doesn't have network session enabled? This is true, unfortunately. Network session is only enabled starting with Sierra/iOS10 and I think EWS uses El Capitan.
Comment on attachment 291823 [details] Fix debug build with network session disabled. r=me
Committed r207454: <http://trac.webkit.org/changeset/207454>