Re: [XForms] Problem with fdesign (fdesigns menu bar) (fwd)

[Clive Stubbings]

Hi,

There has been a regression in the xorg libX11

It is likely this is your issue - it was spotted in one of my xforms programs a 
few weeks ago by one of my users.

XStoreName used to tolerate a NULL pointer (it checked before using it). New 
code has been added ahead of that check.

If your system has recently updated its libraries, thats likely the cause.

I believe it has now been fixed upstream thanks to the person who spotted the 
problem feeding the cause back to the developers and a new version should come 
through in due course.

If you need a quicker fix, hack the library to make sure it doesn't pass a NULL 
pointer to XStoreName.

Cheers
Clive



On Sun, 27 Jun 2021, ternaryd wrote:

> On Sat, 26 Jun 2021 15:47:12 -0700
> Coby Hochstein <cjh39@cox.net> wrote:
>
> > Hello,
> >
> > when I load fdesign and click on the "File"
> > menu bar fdesign segmentation faults.
> > I'm running xforms-1.2.4
> >
> > (gdb) run
> > Starting program: /usr/local/bin/fdesign
> > [Thread debugging using libthread_db enabled]
> > Using host libthread_db library
> > "/lib/arm-linux-gnueabihf/libthread_db.so.1".
> >
> > Program received signal SIGSEGV, Segmentation
> > fault.
> > strlen () at ../sysdeps/arm/armv6/strlen.S:26
> > 26 ../sysdeps/arm/armv6/strlen.S: No such
> > file or directory.
> > (gdb)
>
>
> > Any idea ?
>
> fdesign is calculating the string length of a
> string pointing to NULL.
>
> Use a version of fdesign compiled with debugging
> enabled, run it again until crash, and check the
> coredump in gdb. Use the "up" command until you
> reach a stack level belonging to fdesign (or
> xforms). You should see which pointer is NULL.
> Then you can try to figure out, why it is NULL
> and how to fix it.
>
>    $ ulimit -c unlimited
>    $ ./fdesign ...
>    $ gdb ./fdesign coredump
>    (gdb> up
>    ...
>
> you can query the value of any variable at the
> time of the crash with
>
>    (gdb) p varname
>
> HTH
>
> --
> Cris