4 (kill -s USR1 $$; echo b:$?; exit 3)
5 echo c:$? # does not execute
9 trap "echo Trap; return" USR1
13 # It's debatable what is the correct value above.
14 # Does 'return' in trap sees $? == 2 or $? == 3?
15 # IOW: after (kill..), does shell first wait for its completion
16 # and sets $?, then checks pending signals and runs a trap handler,
17 # or does it first checks pending signals and runs handler?
18 # hush does the former, and prints 3.