more logical fix to bug by using exist left / right args

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Author: carm

src/libprojectM/MilkdropPresetFactory/Expr.cpp

@@ -160,18 +160,22 @@ float TreeExpr::eval_tree_expr ( int mesh_i, int mesh_j )
 	/* Safe guard in case the user gave a partially written expression */
 	if (left == NULL) {
 		if (infix_op == Eval::infix_mult)
-			return 1;
+			left_arg = 1;
 		else
-			return 0;
+			left_arg = 0;
 	}
+	else
+		left_arg = left->eval_tree_expr ( mesh_i, mesh_j );
 
-	left_arg = left->eval_tree_expr ( mesh_i, mesh_j );
-
-	/* Safe guard */
-	if (right == NULL)
-		return left_arg;
-
-	right_arg = right->eval_tree_expr ( mesh_i, mesh_j );
+	/* Safe guard in case the user gave a partially written expression */
+	if (right == NULL) {
+		if (infix_op == Eval::infix_mult)
+			right_arg = 1;
+		else
+			right_arg = 0;
+	}
+	else
+		right_arg = right->eval_tree_expr ( mesh_i, mesh_j );
 
 
 	switch ( infix_op->type )

src/projectM-qt/qprojectm.hpp

@@ -35,13 +35,18 @@ class QProjectM : public QObject, public projectM {
 			presetSwitchedSignal(hardCut, index);
 		}
 
+		void presetSwitchFailedEvent(bool hardCut, unsigned int index, const std::string & message) const {
+			presetSwitchFailedSignal(hardCut, index, message);
+		}
+
 		void presetRatingChanged(unsigned int index, int rating,
 						PresetRatingType ratingType) const {
 			 presetRatingChangedSignal(index, rating, ratingType);
 		}
 
 	signals:
 		void presetSwitchedSignal(bool hardCut, unsigned int index) const;
+		void presetSwitchFailedSignal(bool hardCut, unsigned int index, const std::string & message) const;
 		void presetRatingChangedSignal(unsigned int index, int rating,
 				PresetRatingType ratingType) const;