Re: Possible regression in 'wait' command

[Chet Ramey]

On 5/13/21 3:44 PM, Jonas Alfredsson via Bug reports for the GNU Bourne 
Again SHell wrote:

> Bash Version: 5.1
> Patch Level: 0
> Release Status: release
>
> Description:
> If one has a script similar to this:
>
> ```bash
> trap 'echo "Received SIGHUP"' HUP
>
> sleep 5m &
> child_pid=$!
>
> wait -n ${child_pid}
> wait -n ${child_pid}
> ```
>
> and you send in the system signal SIGHUP the first `wait` will exit (as 
> expected)
> and the message "Received SIGHUP" will be printed. However, since we have a
> second `wait` it should catch further execution and wait for the child once 
> again.

Thanks for the report. The issue is a change between bash-5.0 and bash-5.1
to understand PID arguments with -n. The job state wasn't restored upon
receipt of all trapped signals and interfered with subsequent calls to
`wait -n'.

Chet

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