Re: Clarification needed on signal spec EXIT

[Chet Ramey]

On 10/21/12 7:35 AM, Francis Moreau wrote:

>> Yes, this is a bug in bash-4.2.  The subshell doesn't properly reinitialize
>> the traps if a trap has already been set in the parent.  This was fixed in
>> late July and will be in the next version of bash.
> 
> That doesn't explain the following (taken from a previous post):
> 
>   Even weirder: if the subshell exits by calling "exit 1", then the trap
>   handler is not called at all regardless of whether or not the "trap
>   main_cleanup EXIT" is commented you.
> 
>   To make that case work, you need to use the "( ... ) &" construct
>   instead of "{ ... } &" one.

I think I understand this, but let me make sure.  Where are you putting
the `exit 1'?  If you put it as the last statement in task_in_background,
it works fine.  If you put it after the call to task_in_background in the
lambda subshell, it works fine.  (Both cases with the parent's EXIT trap
commented out and using a brace group.)

Do you mean to replace the call to task_in_background in the lambda
subshell with `exit 1'?  If so, you're right that it doesn't work in
bash-4.2.  It's the same fix from the same bug report:

http://lists.gnu.org/archive/html/bug-bash/2012-07/msg00084.html

The fixes for that report are all in the bash-20120727 snapshot, if you
want to look at that in the devel branch of the git tree on savannah.

Chet
-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, ITS, CWRU    chet@case.edu    http://cnswww.cns.cwru.edu/~chet/