[rules-users] drools solver move factory crash

hello the new version of the drools-solver supports multiple move factories. i happily split my move factory to take advantage of the relativeSelection parameter. now the problem is that not all move factories can produce moves for every possible current solution. and the org.drools.solver.core.localsearch.decider.selector.MoveFactorySelector crashes, when a move factory does not return a single move. public final List<Move> selectMoveList(StepScope stepScope) { List<Move> moveList = moveFactory.createMoveList(stepScope.getWorkingSolution()); if (shuffle) { Collections.shuffle(moveList, stepScope.getWorkingRandom()); } if (relativeSelection != null) { int selectionSize = (int) Math.ceil(relativeSelection * moveList.size()); if (selectionSize == 0) { selectionSize = 1; } moveList = moveList.subList(0, selectionSize); // <-- CRASH, if moveList is empty } return moveList; } currently i solve it by always returning at least a "null-move". but a better solution would be to change the MoveFactorySelector.selectMoveList(), so that it tests for an empty list. best, tim