[SCIP] 1st section in .lp file

[Hartmut Henkel]

Hello,

for this short program

  Minimise
    slack: d
  Subject To
    d >= 3
  End

scip provides "objective value: 0" and "d = 100000" as result without
error. This can be misleading for the user (how to fix it without
introducing incompatilility?). But soplex rightly spots the error and
tells: "This seems to be no LP format file". The reader_lp.c code for
scip shows, that everything before the 1st detected section is treated
as comment. I guess that a correct "Min/Max" section should be the 1st
and mandatory (e. g., the FICO manual says so). Actually the current
scip code allows to garble sections and have the "Min/Max" section
anywhere between other sections (then without typo the result is right),
whereas soplex seems to enforce an order, and it also enforces markers
starting at the begin of line, which scip does not.

Best Regards
Hartmut