Incorrect behavior of Eval(int& stackSize)

[a-shahba]

Comparing v2.2.6 with v2.3.2, there is a change in the behavior of Eval(int& stackSize) which is most likely a bug. When the expression has only a single return value, Eval(int& stackSize) always returns 0. The following code demonstrates this issue

#include <iostream>
#include <string>
#include "muParser.h"

int main(){

    double p1, p2;
    int nc1, nc2;

    mu::Parser parser1;
    parser1.DefineVar("X", &p1);
    parser1.SetExpr("10.0");

    mu::Parser parser2;
    parser2.DefineVar("X", &p2);
    parser2.SetExpr("X + 2");

    std::cout << "\nParser1: Expected to be 10\n";
    p1 = 1.0;
    auto val1 = parser1.Eval(nc1);
    for (unsigned ii = 0; ii < nc1; ++ii) {
        std::cout << ii << "-th component:" << val1[ii] << std::endl;
    }

    std::cout << "\nParser2: Expected to be 12\n";
    p2 = 10;
    auto val2 = parser2.Eval(nc2);
    for (unsigned ii = 0; ii < nc2; ++ii) {
        std::cout << ii << "-th component:" << val2[ii] << std::endl;
    }

    return 0;
}

[beltoforion]

confirmed

[beltoforion]

fixed