fix remove_extra_brackets undoing work of post-processing step

inc/expression.hpp

@@ -277,6 +277,21 @@ public:
 			return "Invalid operator";
 		}
 	}
+
+	int negative_operator(void) const
+	{
+		if (t != OPERATOR)
+		{
+			return 0;
+		}
+
+		return (v.o == SUB || v.o == DIV);
+	}
+
+	static int is_negative(Operator o)
+	{
+		return (o == SUB || o == DIV);
+	}
 };
 
 struct Operation

src/syntaxer.cpp

@@ -709,6 +709,12 @@ static void remove_extra_brackets(std::vector<Expression::Token>& tv)
 				continue;
 			}
 
+			// check specifically if the opening undoes applied fixes
+			if (Expression::Token::is_negative(get_prior_mop(tv, get_mop_location(tv, r.start))))
+			{
+				continue;
+			}
+
 			open_brackets(tv, r);
 		}
 	}