signals ignored in a subshell

[Oğuz]

>
> That's not how read is defined to behave. wait has special wording defining
> what happens when it receives a signal. Bash default mode behaves as I
> described previously -- trapping the signal and returning from the handler
> results in the read being restarted -- and posix mode will run the trap
> handler before returning from the `read' builtin.
>

Okay, you're right, in posix mode the behavior is as expected. However I
still didn't get why job controls being enabled/disabled changes the way an
interactive shell handles signals in posix mode. Like

$ set -o posix
$
$ trap 'echo foo' INT
$
$ read
^Cfoo
$ sleep 5
^C
$
$ set +m
$
$ read
^Cfoo
$ sleep 5
^Cfoo

Is there a race condition here or does posix mandate this behavior for
built-in utilities?


-- 
Oğuz