xboard/gnuchess engine settings dialog crash

[JonasThiem]

Hi, fedora 17 currently ships xboard 4.5.2a and GNU Chess 5.08, and when opening xboard without parameters and opening engine settings, it will crash (100% reproducable). Other engines' settings seem to work fine.

Crash looks like this:
(gdb) run
Starting program: /usr/bin/xboard
Detaching after fork from child process 8864.

Program received signal SIGSEGV, Segmentation fault.
LayoutChild (w=0xcd8870) at Form.c:693
693 FormConstraints ref_form = (FormConstraints)ref->core.constraints;
(gdb) backtrace
#0 LayoutChild (w=0xcd8870) at Form.c:693
#1 0x0000003fd16240df in Layout (fw=0xcd86e0, width=<optimized out>,
height=<optimized out>, force_relayout=1) at Form.c:565
#2 0x0000003fd16237fa in XawFormChangeManaged (w=0xcd86e0) at Form.c:1022
#3 0x0000003fedc28cb1 in ?? () from /lib64/libXt.so.6
#4 0x0000003fedc28cb1 in ?? () from /lib64/libXt.so.6
#5 0x0000003fedc2a2a8 in XtRealizeWidget () from /lib64/libXt.so.6
#6 0x0000000000455ad3 in GenericPopUp (option=0x8ea5d8,
title=<optimized out>, dlgNr=0) at xoptions.c:1604
#7 0x0000003fedc143ee in XtCallCallbacks () from /lib64/libXt.so.6
#8 0x0000003fedc4913d in ?? () from /lib64/libXt.so.6
#9 0x0000003fedc49591 in ?? () from /lib64/libXt.so.6
#10 0x0000003fedc4a32d in _XtTranslateEvent () from /lib64/libXt.so.6
#11 0x0000003fedc2281b in XtDispatchEventToWidget () from /lib64/libXt.so.6
#12 0x0000003fedc22f6e in ?? () from /lib64/libXt.so.6
#13 0x0000003fedc23034 in XtDispatchEvent () from /lib64/libXt.so.6
#14 0x0000003fedc2ed59 in XtAppProcessEvent () from /lib64/libXt.so.6
#15 0x0000003fedc234ad in XtAppMainLoop () from /lib64/libXt.so.6
#16 0x0000000000406a01 in main (argc=1, argv=<optimized out>) at xboard.c:2633
(gdb)

[hgm]

Indeed, GNU Chess has no options, and some Xlib implementations cannot handle it when you try to pop up an empty dialog. So current XBoard versions test for this condition, and then pop up a notice box with the message that the engine has no options, in stead of the Engine Settings dialog.

With these obsolete XBoard versions the only work-around is to not open the Engine Settings dialog for engines that have no options. A better solution is to upgrade to a modern version.