[X2go-dev] Segmentation fault with x2goclient

[Martin Oehler]

Hi Mike,

On Sun, Jun 05, 2011 at 06:54:04PM +0200, Mike Gabriel wrote:
> On So 05 Jun 2011 17:24:10 CEST Martin Oehler wrote:
> 
> I encounter such inconsistencies, as well, when working with X2go
> client. I have added a work around to python X2go to catch these
> irregularities. This workaround was put together at times that
> x2goserver was not yet a Git project (thus, at a time I had no
> influence on the server code myself).

we use the x2gothinclient setup (booted from a Knoppix) at various 
installations with GPG cards connected to a LDAP or an ADS with 
very good results so far. Most patches I needed were of rather 
cosmetic type (putting the card back after a session suspend, clearing 
the username inside the card after a session and so on). The x2go 
system is now upgraded since the display manager mode is available
(and one doesn't need an LDAP server for only providing the session 
type, thanks a lot to Heinz for this).

In short: so far, the bugs are bearable for the benefit. Sometimes
a session seems to be crashed and needs a reset but it's happening 
not very often.

> >Can we discuss a bugfix for this?
> 
> Sure!
> 
> >I really don't know why the DISPLAY-line is returned for a short time
> >after a session suspend, the 52 can be seen in the normal one-line-output
> >from x2golistsessions.
> 
> You do not seem like having an idea, yet? If you can find a hint,
> let me know. I may find time to look at code more closely on
> Tuesday/Wednesday.

I think I have a precise idea, it's the statement

  print "DISPLAY=$display\n";

in line 49 of x2goumount-session. After removing the line the 
session reconnect is stable again (there are only a few results
when searching the x2goserver package with a grep for DISPLAY).

We could declare this a fix but since there is a lot of command output 
parsing I would feel better if someone who is more familiar with the 
code could affirm that this line isn't needed somewhere else. So far
I have no problems with this change.

> If you use pyhoca-gui and start it from the command line, you can
> encounter such issues in irregular intervals, as well. Whenever they
> occur, some output is shouted to stderr and you won't miss it...

I'm very sorry, I didn't test pyhoca-gui or cli yet.

Kind regards,
Martin