Hi,
dash unwinds too far before running EXIT handlers, causing e.g.
redirections to be dropped in subshells when those subshells should have
no way of dropping them.
eval '(trap "echo bug" EXIT)' >/dev/null
The problem is easy enough to see: EV_EXIT causes longjmp() all the way
back to main(), even from within the subshell, and all redirections will
dropped regardless of whether they were created in the parent shell or
the subshell.
The problem is not limited to redirections:
f() { (trap "echo \$var" EXIT); }
var=bad
var=ok f
This prints "bad", when it should print "ok". Here, the local variable
is dropped not in main(), but during the unwind process.
One way to fix this is to install an exception handler in evaltree(nr)
to prevent exceptions bubbling up too far. It can just call exitshell()
from there. It is not clear to me yet whether this is the best way.
Cheers,
Harald van Dijk
