[Bug-glpk] Crash in 4.38

[Wenchel, Seth]

Hello all,

I'm running 4.38 on winXP (inside a VM on top of Mac OS 10.5).  When I try
to optimize the attached file I get the following error:

Assertion failed: xlcmp(env->t_last, t) <= 0
Error detected in file ..\src\glplib10.c at line 109

The attached file is the smallest example I constructed that fails.  The few 
that I tried smaller than this worked.  Of course, this problem is tiny 
compared to what I'd really like to run.

The problem has the following basic structure:

Min z = SUM over type[ SUM over location (Overage_{type,location} +
Underage_{type,location})]

S.t.

Foreach type [ Foreach location [ SUM over group (k_{type,
group}*y_{location, group}) -Overage_{type,location} +
Underage_{type,location} address@hidden

Foreach group [ SUM over location (y_{location, group}) = 1

Y_{location, group} are binary

So I have a number of groups which I can put at any location.  Each group
has needs of various types (defined by k_{type,group}).  Each location has
various resources (defined by address@hidden).  The idea is that I need
to put groups at locations such that I meet their needs as closely as
possible and of course, I can't split a group across multiple locations.

Thanks for all of your work.  Please let me know if you need any more info
from me.
Regards,
Seth
--
Sooner or later any problem will get big enough that you can¹t solve it.
But it¹s nicer if you make it later.
    ~A. Rosenberg

PSO_test_small.lp
Description: PSO_test_small.lp