Transform exit handlers of the form
trap cleanup EXIT [INT] [TERM] [QUIT] [HUP] [ERR]
(where cleanup is idempotent)
to
trap cleanup EXIT
This fixes a common bash antipattern.
Each of the above signals causes the script to exit. For each signal,
bash first handles the signal by running `cleanup` and then runs
`cleanup` again when handling EXIT.
(Exception: `vscode/*` prevents the second run of `cleanup` by removing
the trap in cleanup`).
Simplify the cleanup logic by just trapping exit, which is always run
when the script exits due to any of the above signals.
Note: In case of borgbackup, the exit handler is not idempotent, but just
trapping EXIT guarantees that it's only run once.
Fixes a regression on OS X introduced by f83af95.
Don't use --tmpdir for mktemp, because that flag doesn't exist on OS X.
However, using -t is deprecated in GNU coreutils, so as suggested by
@ip1981 we're now using parameter expansion on ${TMPDIR:-/tmp} to
provide /tmp as a fallback if TMPDIR is not set and use it instead.
Also use this approach for nix-prefetch-cvs now in order to stay
consistent.
Reported-by: Vladimir Kirillov <proger@wilab.org.ua>
Tested-by: Igor Pashev <pashev.igor@gmail.com>
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
