ufuzz failure

[alexlamsl]

// original code
// (beautified)
var _calls_ = 10, a = 100, b = 10, c = 0;

function f0(a) {
    {
        var arguments_2 = function f1(b_1, await_1) {
            {
                {
                    var expr3 = "object";
                    for (a in expr3) {
                        c = 1 + c;
                        var await = expr3[a];
                        {
                            var expr4 = await && typeof await.undefined == "function" && --_calls_ >= 0 && await.undefined(24..toString());
                            for (var key4 in expr4) {
                                c = 1 + c;
                                var foo_1 = expr4[key4];
                            }
                        }
                    }
                }
            }
            if ((c = c + 1) + b_1) {
                for (var brake7 = 5; b-- && brake7 > 0; --brake7) {
                    L10880: {
                        {
                            var foo = function f2() {
                            }();
                        }
                    }
                }
            } else {
                var arguments = function f3(await) {
                    if (5 in {}) {
                    } else {
                        return c = 1 + c, (2 && "function") == "b" > "bar" || await_1 && (await_1.b = "" - 25 & ("object" || false));
                    }
                }();
            }
        }("object");
    }
    {
        return a--;
    }
}

var a = f0(-4);

console.log(null, a, b, c, Infinity, NaN, undefined);

// uglified code
// (beautified)
var e = 10, u = 10, r = 0;

(function f0(a) {
    (function f1(b_1, await_1) {
        var n, i, f, t, arguments, o = "object";
        for (a in o) {
            for (f in r = 1 + r, i = (n = o[a]) && "function" == typeof n.undefined && 0 <= --e && n.undefined("24")) {
                r = 1 + r, i[f];
            }
        }
        if ((r += 1) + b_1) {
            for (t = 5; u-- && 0 < t; --t) {}
        } else {
            arguments = function f3(await) {
                if (!(5 in {})) {
                    return r = 1 + r, await_1 && (await_1.b = 0);
                }
            }();
        }
    })("object"), a--;
})(-4), console.log(null, -4, u, r, Infinity, NaN, void 0);

original result:
null 5 4 7 Infinity NaN undefined

uglified result:
null -4 4 7 Infinity NaN undefined

// reduced test case (output will differ)

// (beautified)
function f0(a) {
    (function f1() {
        var expr3 = "object";
        for (a in expr3) {}
    })();
    return a;
}

var a = f0();

console.log(a);
// output: 5
// 
// minify: undefined
// 
// options: {
//   "compress": {
//     "hoist_vars": true,
//     "keep_infinity": true,
//     "passes": 1000000,
//     "unsafe": true
//   },
//   "keep_fargs": true,
//   "keep_fnames": true,
//   "toplevel": true,
//   "mangle": {
//     "v8": true
//   },
//   "output": {
//     "v8": true
//   },
//   "validate": true
// }

minify(options):
{
  "compress": {
    "hoist_vars": true,
    "keep_infinity": true,
    "passes": 1000000,
    "unsafe": true
  },
  "keep_fargs": true,
  "keep_fnames": true,
  "toplevel": true,
  "mangle": {
    "v8": true
  },
  "output": {
    "v8": true
  }
}

Suspicious compress options:
  evaluate
  reduce_vars
  sequences
  unused

Suspicious options:
  keep_fnames
  toplevel