Re: Bug in bash 4.4-beta: suspending and restarting "man" program

[Chet Ramey]

On 11/10/15 2:15 PM, Keith Thompson wrote:
> But there's still a mystery here. Why does it behave differently under rxvt
> vs. xterm,
> and why does that difference show up in bash 4.4-beta but not in 4.3.30?
> (Both versions of bash are built from source on the same system.)
> 
> Running bash 4.3.30 under either xterm 261 or rxvt v2.6.4, I get:
> 
> bash-4.3$ trap
> trap -- '' SIGTSTP
> trap -- '' SIGTTIN
> trap -- '' SIGTTOU
> 
> and Ctrl-Z works correctly.
> 
> Running bash-4.4-beta under xterm, I get
> 
> bash-4.4$ trap
> trap -- '' SIGTTOU
> 
> and Ctrl-Z works correctly.  Running bash-4.4-beta under rxvt, I get:
> 
> bash-4.4$ trap
> trap -- '' SIGTSTP
> trap -- '' SIGTTIN
> trap -- '' SIGTTOU
> 
> and Ctrl-Z *doesn't* work.

It seems like you need to figure out why rxvt starts the shell with
SIGTSTP ignored.  It doesn't seem like anything that the system /bin/sh
or the bash version you're running does, since xterm doesn't exhibit
this behavior.

The difference between bash-4.3 and bash-4.4 is a bug fix: if the shell
is started with SIGTSTP ignored (any signal, really), it's supposed to
pass that setting on to the children it invokes.  bash-4.3 didn't do that
in this case, and bash-4.4 does.

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/