[Help-glpk] GLPK 4_23 internal error in call back

[ms]

Hi,

I am using GLPK 4.23 for solving a MIP problem and using call back suggested
by Andrew Makhorin to exit when the MIP gap is <= 5%

---------------------------------------------------
void cb_func(glp_tree *tree, void *info) 
{     if (glp_ios_reason(tree) == GLP_IBINGO) 
      {  if (glp_ios_mip_gap(tree) < 0.10) 
            glp_ios_terminate(tree); 
      } 
      . . . 
} 

int main(void) 
{     glp_prob *mip; 
      glp_iocp parm; 
      . . . 
      glp_init_iocp(&parm); 
      parm.cb_func = cb_func; 
      glp_intopt(mip, &parm); 
      . . . 
} 
-------------------------------------------------------------------------------------

The call back works fine upto certain point when I get the following error:

GLPK internal error: lp->tree == NULL; file ..\src\glpapi01.c, line 1147

I compiled the source using VS2005 and calling the API's in C#. If I don't
use use call backs the program works fine. But I don't have control over the
mip gap. Any suggestion will be appreciated.

Sam
-------------output-----------------------------------------
11:02:09 AM *  1341:   objval =  8.225886544e+002   infeas = 
5.280220705e-013 (0)
11:02:09 AM OPTIMAL SOLUTION FOUND
11:02:09 AM Integer optimization begins...
Gap = 1.79769313486232E+308 Reason = 6
Gap = 1.79769313486232E+308 Reason = 7
11:02:10 AM +  1341: mip =     not found yet >=              -inf        (1;
0)
Gap = 1.79769313486232E+308 Reason = 1
Gap = 1.79769313486232E+308 Reason = 3
Gap = 1.79769313486232E+308 Reason = 4
Gap = 1.79769313486232E+308 Reason = 5
Gap = 1.79769313486232E+308 Reason = 7
11:02:13 AM +  1341: mip =     not found yet >=  8.225886544e+002        (2;
0)
Gap = 1.79769313486232E+308 Reason = 1
Gap = 1.79769313486232E+308 Reason = 3
Gap = 1.79769313486232E+308 Reason = 4
Gap = 1.79769313486232E+308 Reason = 5
Gap = 1.79769313486232E+308 Reason = 7
11:02:17 AM +  1345: mip =     not found yet >=  8.225886544e+002        (3;
0)
11:02:17 AM GLPK internal error: lp->tree == NULL; file ..\src\glpapi01.c,
line 1147

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