[Clp] Save and restore an LP solution/basis?

[John Forrest]

Francis,

The problem is bad documentation.

In test_basis.cpp at lines 34 and 39 there is

restore->primal(1);

This tells primal to believe in the incumbent primal solution more than
the basis flags.  The solution is all zero at this point so the code
will flip some slacks to their other bound - not a good idea.

If you change those lines to 

restore->primal();

it is all fine as then it ignores the primal solution.

However a more robust solution is to save the values.  So I would
suggest leaving the lines as primal(1) and modifying line 23 to

original->writeBasis("sav.bas",true);

John Forrest