Postsolve: DuplicateColumn::undo message ignores output_flag #3565

Postsolve: DuplicateColumn::undo message ignores output_flag

highs duplicate-column-printf.lp with output_flag = false still prints

HighsPostsolveStack::DuplicateColumn::undo Col is nonbasic at zero with upper bound of 1

because it is a bare printf (HighsPostsolveStack.cpp:751). In a debug build the assert(111 == 679) after it fires. The comment above it (line 733) asks "what if it's at zero with a finite upper bound?". This LP is such a case (x5 in (-inf, 1], merged with its duplicate x43). In release, the clean-up solve after postsolve returns the right answer (Optimal, -55, same as presolve off).

3565.lp.txt

3565.mps.txt