freebsd stable - Aug 2015 - Latest stable (r287104) bash leaves zombies on exit

> Hi Pete!
>
> I cannot reproduce the error, but I'm using fvwm. Can you give a
step-bystep instruction to reproduce the error?
>
> nik
Hello Nik, thanks for looking at this for me - I havent yet found a reliable way
to reproduce it unfortunately. It seems to happen on wiindows where I have
run 'vi' or where I have logged in to another machine on ssh, but then
thats mainly what I do in my wondows, so its hardly surprising ;-(

Is there anything I can do to investiagett eh status of the stuck processes.
I have managed to get 4 in the last hour here.

-pete.

Pete French wrote:
> I updated to stable yesterday, plus updated all my porst to
> the latest pecompiled packages, but I am now seeing odd problems
> with bash on exit. Sometimes it quits, but leaves a zombie
> process... e.g
> 
>  PID TT  STAT    TIME COMMAND
> 44308 v0  IW   0:00.00 -bash (bash)
> 44312 v0  IW+  0:00.00 /bin/sh /usr/local/bin/startx -listen_tcp
> 44325 v0  IW+  0:00.00 xinit xterm -listen_tcp -- /usr/local/bin/X :0 
> -auth /ho
> 44328 v0  IW   0:00.00 /usr/local/bin/wmaker
> 44340 v0  S    0:03.35 /usr/local/bin/wmaker --for-real
> 49101  0- Z+   0:02.73 <defunct>
> 49314  1- Z+   0:00.17 <defunct>
> 56068  2  Ss   0:00.01 bash
> 56498  2  R+   0:00.00 ps
> 56074  3  Is   0:00.01 bash
> 56076  3  S+   0:00.00 mail freebsd-stable at freebsd.org
> 56308  4  Is+  0:00.01 bash
> 
> Thats the current 'ps' on this machine. The bash processes are
running
> inside an xterm, so am not sure if the issue is with bash or the
> terminal. Kind of puzzled!
I can reproduce this easily, although not every time.

Running 10.2 under KDE, with bash as a default shell:
start xterm from a KDE 'konsole', then move to within the xterm
and try closing it (^D or exit). More often than not the xterm
will block and stay open, the bash process within goes <defunct>.

A normal kill of xterm has no effect, although a kill -9 to the
xterm blows away the xterm and the init process then clears
the bash zombie leftover. Seems like running a simple command
like 'date' in xterm before trying to close it does increase
the likelihood that xterm will block on exit.

> Currently I have to reboot the machine periodicly once I have 
> accumulated
> enough zombies to be annoying. Its not really a long term solution 
> though.
There is no need to reboot, just kill -9 the hanging xterm processes
and the init will clear the zombies.

   Mark