[Bug-glpk] spydual crash in GLPK 4.57

[Sascha Brügmann]

Hello everyone,
I solve many problems with GLPK and every 5000-nth problem or so (no 
fixed number, just a hint how often it occures) GLPK terminates in the 
middle of integer-solving my problem. The following message is then printed:
Assertion failed: tcol[csa->p] != 0.0
Error detected in file ..\src\simplex\spydual.c at line 999

I invoke GLPK from a Java application using glpk-java. glpk-java is able 
to catch some occurances of this error and throw them as 
org.gnu.glpk.GlpkException such that my programm can catch them and just 
restart GLPK (works fine!). Unfortunately most of the occurances of the 
error kill GLPK and the JVM instantly and there is nothing I can do. I 
have to notice the crash manually and restart my application manually.

All my problems are only slight variations of each other. Until now I 
couln't blame specific variations of my problem to cause this error 
because when I let GLPK re-solve the same problem it finds a feasible 
solution (all my problems have a feasible solution).

Parameters I invoke GLPK with:
        glp_prob lp_native = GLPK.glp_create_prob();
        //add constraints...

        final glp_iocp iocp = new glp_iocp();
        GLPK.glp_init_iocp(iocp);
        iocp.setPresolve(GLPKConstants.GLP_ON);
        iocp.setBr_tech(GLPKConstants.GLP_BR_PCH);
        iocp.setBt_tech(GLPKConstants.GLP_BT_BPH);
        iocp.setMsg_lev(GLPKConstants.GLP_MSG_ON);
        iocp.setPp_tech(GLPKConstants.GLP_PP_ALL);
        iocp.setBinarize(GLPKConstants.GLP_ON);
        iocp.setTm_lim(123456);

        GLPK.glp_intopt(lp_native, iocp);

Regards Sascha