SSH connection hanging on logout

[John Bowman]

> The patch does not work for protocol 1:
> 
> while [ 1 ] ; do ssh -p 2222 -o Protocol=1 -oForwardX11=no djm at localhost dd if=/dev/zero bs=1024 count=100 | wc -c ; done
> 
> Write failed flushing stdout buffer.
> 100+0 records in
> 100+0 records out
>   16384
> Write failed flushing stdout buffer.
> 100+0 records in
> 100+0 records out
>   20480
> Write failed flushing stdout buffer.
> 100+0 records in
> 100+0 records out
>   20480
> Write failed flushing stdout buffer.
> 100+0 records in
> 100+0 records out
>   20480
> 
Interesting. First of all, this reminds me to point out that the patch only
fixes the hang-on-exit bug for Protocol 2 anyway. Which OS and which
platform did this occur on? On RedHat Linux 6.2 no data loss appears to
occur under Protocol 1. But I haven't tested it extensively since under
this protocol it doesn't fix the bug anyway.

while [ 1 ] ; do ssh -o Protocol=1 -oForwardX11=no localhost dd if=/dev/zero bs=1024 count=100 | wc -c ; done
100+0 records in
100+0 records out
 102400
100+0 records in
100+0 records out
 102400
100+0 records in
100+0 records out
 102400
100+0 records in
100+0 records out
 102400
100+0 records in
100+0 records out
 102400
100+0 records in
100+0 records out
 102400
100+0 records in
100+0 records out
 102400

In any case, given what you have found, I agree that users who are still
supporting Protocol 1 should either not apply the patch at all or else modify
it to call chan_shutdown_read only under Protocol 2.

-- John Bowman
http://www.math.ualberta.ca/~bowman