Of interest, is bug 1710926 : if I set `browser.download.improvements_to_download_panel` to `true`, then files are downloaded to the default Downloads directory, instead of a temporary directory, and the downloads panel is shown, instead of a dialog to ask the user what to do with the file.
Once that setting becomes true by default, we can simply remove the `TMPDIR` hack.
Of interest, is bug 1710926 : if I set `browser. download. improvements_ to_download_ panel` to `true`, then files are downloaded to the default Downloads directory, instead of a temporary directory, and the downloads panel is shown, instead of a dialog to ask the user what to do with the file.
Once that setting becomes true by default, we can simply remove the `TMPDIR` hack.