Uglifyjs: Bug in `inline`

Created on 12 Jun 2017 · 1Comment · Source: mishoo/UglifyJS

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

function f0() {
    function f1(undefined) {
        for (var brake1 = 5; ++a && brake1 > 0; --brake1) {
            var a = function f2() {
                c = 1 + c, (-5 && "function") & (a && (a.foo = NaN % ([ , 0 ].length === 2))) ^ (a = (a += [] % "") === "object" - "object");
                c = 1 + c, ([] / -2 === 25 % 5) <= ((/[a2][^e]+$/ == /[a2][^e]+$/) < (2 >= -4));
            }(a++ + []);
        }
        c = c + 1;
    }
    var a_1 = f1();
    function f3() {
        {
            var b_1 = {
                a: (c = 1 + c, ~({} << 2) << ((c = c + 1, 2) | 38..toString() / 22)),
                0: (c = 1 + c, (bar_1 && (bar_1.foo = "foo" < /[a2][^e]+$/ & ("foo" ^ null))) / (c = c + 1, 
                -0 * 22)),
                Infinity: (c = 1 + c, ([] ^ -4) % (b_1 = "undefined" + 24..toString()) + ("function" & 3 && false >>> 24..toString())),
                1.5: (c = 1 + c, (-2 < 23..toString()) * (-5 << undefined) === (b_1 = /[a2][^e]+$/ * 25 === ("foo" ^ 25))),
                undefined: (c = 1 + c, (-0 >>> -5 ^ "function" * -3) - (b_1 && (b_1.c = "object" >> NaN >> (true, 
                -5))))
            }.length, bar_1 = a++ + (b += a);
            {
                c = 1 + c, ((23..toString() ^ "") - (bar_1 = NaN && -4)) / (b_1 && (b_1[(c = c + 1) + function a_2() {
                }()] = null + "" || -0 ^ [ , 0 ][1]));
                c = 1 + c, ([ , 0 ].length === 2 ^ [ , 0 ][1]) << (b_1 && (b_1[(c = 1 + c, (0 <= NaN !== true - Infinity) << (("foo", 
                "undefined") != "function" / 1))] = Infinity - undefined)) || "number" < false !== (4 | 24..toString());
            }
        }
        {
            var brake11 = 5;
            do {
                b--;
            } while ((c = c + 1) + undefined && --brake11 > 0);
        }
    }
    var foo_1 = f3();
    function f4(arguments_1, a_1, a_1) {
        c = c + 1;
        (c = c + 1) + (b = a);
    }
    var a_1 = f4();
    function f5(parseInt_1, c) {
        function f6(parseInt_1_2, parseInt_1) {
            function f7() {
            }
            var b = f7(2, false);
            function f8() {
            }
            var parseInt_1 = f8("number", null, 0);
            function f9() {
            }
            var parseInt_1_2 = f9(3, -1);
            function f10(parseInt_1, b_1, a_1) {
            }
            var parseInt_1_2_2 = f10(-3);
            function f11(a_1_1) {
            }
            var parseInt_1 = f11();
        }
        var a_1 = f6({}, true, null);
        function f12(a_1_1, Infinity, parseInt_1) {
            var undefined_1 = (c = 1 + c, !([] == /[a2][^e]+$/ ^ ("foo" && ""))), parseInt = (c = 1 + c, 
            ("bar" <= -1 != 23..toString() < 4) < (2 === null == (NaN & 0)));
            var b = (c = 1 + c, (c = c + 1, [ , 0 ][1]) >= ([ , 0 ][1] ^ 3) !== (Infinity >>> "function" ^ -0 == 25));
        }
        var a_1_2 = f12();
        function f13(foo_1_1) {
            var NaN;
            L697216: {
            }
        }
        var c = f13(/[a2][^e]+$/);
        function f14(a_2, a_1) {
            if (c = 1 + c, parseInt_1 && (parseInt_1[--b + --b] += ((-2 ^ 3) == ("undefined" & -4)) >> ((true || "") !== (22 === undefined)))) {
                c = 1 + c, ("" & 23..toString()) >= -3 - {} < ((undefined ^ "function") == ("number" || "function"));
            }
            if (c = 1 + c, ("foo" << "bar" & 4 << true) !== void null << 22 % 23..toString()) {
                c = 1 + c, (null + -2) % (2 - [ , 0 ][1]) || a_1 && (a_1[--b + void b] = delete -1 / (1 << [ , 0 ][1]));
            }
        }
        var NaN_2 = f14(-0);
    }
    var foo_2 = f5(3, -1);
    function f15(c, a_2) {
        var b_2 = (c = c + 1) + [ a++ + +(("number" << 3 ^ ("object" || 25)) <= (0 !== "bar") >> (foo_2 && (foo_2.Infinity = (5, 
        "object")))), a++ + (c = 1 + c, -2 < 23..toString() != "object" >>> Infinity == (null != null) < (22 == 23..toString())), a++, (c = c + 1) + ((c = 1 + c, 
        (NaN ^ true) << (3 ^ "bar") == (-1 || 1, -2 & "")) || 4).toString()[(c = 1 + c, 
        (0 ^ [ , 0 ].length === 2 || -1 & NaN) % ((1 || {}) ^ 24..toString() <= "undefined"))], delete (("number", 
        "undefined") <= (-5 != 3) && ~(38..toString() > 24..toString())) ].b, b = foo_2 && foo_2.null;
        for (var brake24 = 5; (a++ + --b || a || 3).toString() && brake24 > 0; --brake24) {
            try {
                c = 1 + c, (a_1 && (a_1[--b + void function() {
                }()] += (-1 ^ null) >= ("function" >= 2))) != -0 / ([ , 0 ].length === 2) < -3 >>> -0;
            } finally {
            }
            c = c + 1;
            {
            }
            {
                var brake30 = 5;
                L697217: do {
                    c = 1 + c, (c = c + 1, "function") << (-5 >= 3) != (-4 | "number") >= (1 ^ -2);
                } while ((c = 1 + c, ([] - "bar") * (a_2 = "bar" ^ 38..toString()) >>> (([ , 0 ].length === 2) < {}) / (-4 % 3)) && --brake30 > 0);
            }
        }
    }
    var Math_2 = f15();
}

var Infinity_2 = f0();

console.log(null, a, b, c);

```js
// uglified code
// (beautified)
function f0() {
var n = function() {
for (var n = 5; ++t && n > 0; --n) {
var t = (t++, c = 1 + c, t && (t.foo = NaN % (2 === [ , 0 ].length)), t = NaN === (t += [] % ""),
void (c = 1 + c));
}
c += 1;
}(), n = (function() {
var n = {
a: (c = 1 + c, ~({} << 2) << (c += 1, 2 | 38..toString() / 22)),
0: (c = 1 + c, (t && (t.foo = 0)) / (c += 1, -0)),
Infinity: (c = 1 + c, (-4 ^ []) % (n = "undefined" + 24..toString()) + 0),
1.5: (c = 1 + c, -5 * (-2 < 23..toString()) === (n = !1)),
undefined: (c = 1 + c, 0 - (n && (n.c = 0)))
}.length, t = a++ + (b += a);
c = 1 + c, 23..toString(), t = NaN, n && (n[(c += 1) + void 0] = "null"), c = 1 + c,
(2 === [ , 0 ].length ^ [ , 0 ][1]) << (n && (n[(c = 1 + c, 2)] = NaN)) || 24..toString();
var i = 5;
do {
b--;
} while ((c += 1) + void 0 && --i > 0);
}(), c += 1, c += 1, void (b = a)), t = (c = 1 + (c = 1 + (c = -1)), 23..toString(),
c = 1 + c, c += 1, c = 1 + (c = void 0), (3[--b + --b] += 0) && (c = 1 + c, 23..toString()),
c = 1 + c, void (0 != void 0 << 22 % 23..toString() && (c = 1 + c)));
!function(c) {
c += 1, a++, t && (t.Infinity = "object"), a++, c = 1 + c, 23..toString(), 23..toString(),
a++, (c = 1 + (c += 1), 4).toString()[(c = 1 + c, (0 ^ 2 === [ , 0 ].length || 0) % (1 ^ 24..toString() <= "undefined"))];
for (var i = t && t.null, o = 5; (a++ + --i || a || 3).toString() && o > 0; --o) {
try {
c = 1 + c, n && (n[--i + void 0] += !1);
} finally {}
c += 1;
var r = 5;
do {
c = 1 + c, c += 1;
} while (c = 1 + c, ([] - "bar") * ("bar" ^ 38..toString()) >>> ((2 === [ , 0 ].length) < {}) / -1 && --r > 0);
}
}();
}

var a = 100, b = 10, c = 0, Infinity_2 = f0();

console.log(null, a, b, c);

```js
original result:
null 110 99 13

uglified result:
null 110 99 NaN

minify(options):
{
  "compress": {
    "keep_fargs": false,
    "passes": 3
  }
}

Suspicious compress options:
  collapse_vars
  conditionals
  evaluate
  inline
  passes
  reduce_vars
  sequences
  side_effects
  unused

bug

Source