This is about Fedora's Firefox changing the runtime environment for programs it can launch compared with the user's desktop environment. /usr/bin/firefox does: TMPDIR="${TMPDIR:-/var/tmp}" export TMPDIR If it prefers /var/tmp over /tmp, it should do that internally only and not export a $TMPDIR that differs from the rest of the system. Most (all?) API calls that return a temporary directory location default to /tmp if $TMPDIR is not set. Some still look at other environment variables, too, but that is beyond the scope of this ticket. Programs launched by Firefox would be affected by a $TMPDIR that is different than when starting the program normally. At https://fedorahosted.org/fesco/ticket/1365 a patch for Firefox has been demonstrated that would set /var/tmp internally. Firefox should not override system defaults. It may default to /var/tmp (even with no option to override that), but $TMPDIR is not for /var/tmp but /tmp by default ( http://fedoraproject.org/wiki/Features/tmp-on-tmpfs ).
Okay, will look at it.
I'd rather see a patch which moves all temporary data to /tmp (the recent tmpfs) but only downloads are saved to /var/tmp.
So we should remove the TMPDIR from the launch script but patch Firefox to save partial downloads to /var/tmp.
Okay, let's remove the hack we use. The partial file is downloaded to /tmp while we wait for user interaction so the 1GB limit should be enough. Debian uses the same model. Added to firefox-33.0-5.
*** Bug 969658 has been marked as a duplicate of this bug. ***