#237 Memory violation for subsumptive tabling

[Joachim Jansen]

When having the attached in the working directory, executing XSB in the following manner results in a runtime error. The error occurs nondeterministically; sometimes the program exits normally, sometimes it results in an error.

xsb -S -e "[basics], load_dyn('jjansen_xsb.P'), x269(X0, X1, X2, X3)."

The produced output when an error occurs is the following:

[joachim@thither ~/sandbox]$ xsb -S -e "[basics], load_dyn('jjansen_xsb.P'), x269(X0, X1, X2, X3)."
[xsb_configuration loaded]
[sysinitrc loaded]
[xsbbrat loaded]

XSB Version 3.7. (Clan MacGregor) of July 6, 2016
[x86_64-unknown-linux-gnu 64 bits; mode: optimal; engine: slg-wam; scheduling: local]
[Build date: 2017-05-02]

Evaluating command line goal:  
| ?-  [basics], load_dyn('xsb.P'), x269(X0, X1, X2, X3).

| ?- [basics loaded]
[/home/joachim/sandbox/xsb.P dynamically loaded, cpu time used: 0.5680 seconds]
Partial Forward Continuation...
... call_c/1  From /home/joachim/software/idp3_release/bin/xsb-3.7./syslib/standard.xwam
... call_c/1  From /home/joachim/software/idp3_release/bin/xsb-3.7./syslib/standard.xwam

++Error[XSB]: [Runtime/C] 
++Memory violation occurred during evaluation.
++Please report this problem using the XSB bug tracking system accessible from
++       http://sourceforge.net/projects/xsb
++Please supply the steps necessary to reproduce the bug.

++Error[XSB]: [Runtime/C] Exiting XSB abnormally...

Running with a debug executable of XSB simply results in a segfault.