ufuzz failure

[alexlamsl]

https://travis-ci.org/alexlamsl/UglifyJS2/builds/373920501

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

function f0(b) {
    function f1(b_2, bar_1, NaN_1) {
        var bar = a++ + !(!(bar_1 *= 2 & 1) < true % 2 * ("function" * /[a2][^e]+$/)), Math = void a;
        if (a++ + a++) {
            var expr3 = !((!1 != ("a" ^ -2)) + (Infinity < "bar" | (a_2 && (a_2.NaN = 5 && null))));
            for (var key3 in expr3) {
                c = 1 + c;
                var a_2 = expr3[key3];
                L16061: {
                    c = 1 + c, c = c + 1, (-3 != -1) > -5 >> /[a2][^e]+$/;
                    c = 1 + c, bar_1 && (bar_1[!((bar_1 && (bar_1.in = "c" == "c" || null + null)) >>> ("bar" - "b" >>> ("foo" >> 4)))] += (true >> {}) * ("c" + 23..toString()) == (-5 != -2) >> (c = c + 1, 
                    "a"));
                }
            }
        } else {
            switch (typeof foo_1 != "string") {
              case a++ + /[abc4]/.test((a++ + {
                    c: (c = 1 + c, (([ , 0 ].length === 2 ^ 22) > false * "c") << ((0 ^ 38..toString()) === (c = c + 1, 
                    [ , 0 ][1]))),
                    length: (c = 1 + c, c = c + 1, 5 % "" ^ ("c" | -3)),
                    undefined: (c = 1 + c, (3 <= 1 === -0 >>> "a") <= (23..toString() - "function" ^ (-2 && ""))),
                    NaN: (c = 1 + c, NaN_1 && (NaN_1[-(((c = c + 1, 3) < (1 < 4)) + (-0 && -3) / (/[a2][^e]+$/ / true))] = ([ , 0 ].length === 2) - -2 >> (c = c + 1, 
                    true) ^ (this === [] | 22 === -2))),
                    3: (c = 1 + c, [ , 0 ][1] + NaN ^ -5 * 5 ^ (38..toString() === Infinity) <= (NaN_1 && (NaN_1.a += -3 !== ([ , 0 ].length === 2))))
                }[(c = 1 + c, (null >= 22) >> 24..toString() % undefined === (bar_1 = null >= 1) * ("" >> "function"))] || b || 5).toString()):
                c = c + 1;
                break;

              case (c = c + 1) + a_2:
                break;

              case NaN_1:
                try {
                    c = 1 + c, 22 - [ , 0 ][1] - ([ , 0 ].length === 2) / "c" ^ ({} >= NaN) - ("" << "a");
                } finally {
                }
                break;

              case --b + void ((a_2 && (a_2.var = [ , 0 ].length === 2 != {})) / (a_2 && (a_2[(c = 1 + c, 
                (/[a2][^e]+$/ === 5, void "") < (38..toString() - "bar") % (([ , 0 ].length === 2) >> undefined))] += "" % "foo")) % (a_2 &= (this == {}) >= ({} & 24..toString()))):
                break;
            }
        }
    }
    var c_2 = f1(false, -1, undefined);
    function f2(c_2_1) {
        {
            var brake11 = 5;
            do {
                (c = c + 1) + (a-- ? c_2_1 && c_2_1.null : 1 === 1 ? a : b);
            } while ([][a++ + (typeof f4 == "function" && --_calls_ >= 0 && f4((c = 1 + c, (null >= NaN ^ -1 * Infinity) === ("b" & 1) >> (Infinity, 
            "a")), (c = 1 + c, (0, 0) << ("a" ^ "function") !== ("function" >= -4 == (c_2_1 && (c_2_1.NaN = -0 > -3)))), 1))] && --brake11 > 0);
        }
        switch (a++ + -0) {
          case (c = c + 1) + (b = a):
            break;

          case (c = c + 1) + (typeof f0 == "function" && --_calls_ >= 0 && f0("foo")):
            {
                var expr14 = 1 === 1 ? a : b;
                L16062: for (var key14 in expr14) {
                    c = 1 + c;
                    var c_2_1 = expr14[key14];
                    {
                        var brake15 = 5;
                        L16063: while ((c = 1 + c, (c = c + 1, "c" >= /[a2][^e]+$/) | (c_2 = 3 >> "") <= ([ , 0 ][1] & "undefined")) && --brake15 > 0) {
                            c = 1 + c, c = c + 1, (this, "number") && 23..toString() === [];
                        }
                    }
                }
            }
            --b + delete b;
            break;

          case b = a:
            1;
            for (var brake19 = 5; null && brake19 > 0; --brake19) {
                c = c + 1;
            }
            break;

          case /[abc4]/.test(((c = c + 1) + (/[abc4]/.test(((c = 1 + c, ([] ^ "function") > ("bar" === -1) & 38..toString() + {} >> (24..toString(), 
            true)) || b || 5).toString()) || a || 3).toString() || b || 5).toString()):
            switch ((c = c + 1) + void a) {
              case --b + -b:
                c = 1 + c, c_2 && (c_2[--b + ((c = c + 1) + ((c = 1 + c, (("foo" <= [ , 0 ][1]) >> ("" << {})) + ((c_2_1 += 1 != "b") || ("function" || -0))) || 4).toString()[(c = 1 + c, 
                (NaN !== /[a2][^e]+$/) / (-5 !== "object") ^ ([] !== -3 ^ false <= true))] || a || 3).toString()] = 0 != -4 != ("number" || []) ^ (-5 * "b" ^ null > /[a2][^e]+$/));
                break;

              case 0 === 1 ? a : b:
                c = 1 + c, 38..toString() - 1 | -0 << "foo" && (c = c + 1, 24..toString() | this);
                c = 1 + c, c_2_1 && (c_2_1[(c = c + 1) + [ (c = 1 + c, -4 >>> this === (25 === true) != ((c = c + 1, 
                -0) ^ -4 << "object")), (c = 1 + c, ([] & 2) + (1 >= "function") != (-5 >= Infinity) << 2 + "undefined"), (c = 1 + c, 
                (-3 ^ [ , 0 ][1]) / (22 != -1) !== ((c = c + 1, "bar") & ("a" && true))), (c = 1 + c, 
                (([ , 0 ].length === 2) + Infinity ^ ~[ , 0 ][1]) <= (undefined << {}) % (c_2_1 && (c_2_1.foo = "b" || Infinity))), (c = 1 + c, 
                (c_2 && (c_2[b--] /= [] + 38..toString() ^ (c_2 && (c_2.var += undefined === -0)))) / (undefined >>> 0 <= -3 * "a")) ][(c = c + 1) + ((-0 * NaN ^ {} > "c") - ({} * -2 >> (0 === 23..toString())))]] += (38..toString() + ([ , 0 ].length === 2) >= (-3 >= -1)) / (c = c + 1, 
                false <= 38..toString()));
                break;

              case --b + c_2:
                c = 1 + c, ("a" ^ "") < (false ^ "foo") || 1 + "" <= ("function", this);
                c = 1 + c, c = c + 1, c = c + 1, c = c + 1, false;
                break;

              case --b + [ (c = 1 + c, ((25 || 24..toString()) ^ (25 ^ -3)) != !23..toString() < 0 % {}), (c = 1 + c, 
                c_2 >>= (c_2_1 && (c_2_1.c = (null == -1) >> (false ^ 3))) >= (22 == -0 !== (c_2_1 && (c_2_1[(c = 1 + c, 
                (NaN !== 1) + ("number" || "function") && -3 <= "bar" ^ ([ , 0 ][1] || false))] = ([], 
                "b"))))) ]:
                c = 1 + c, (c_2_1 && (c_2_1[[]] = (false != "c") << (-0 >>> false))) !== 23..toString() << -5 < 3 * -4;
                break;
            }
            try {
                {
                }
            } catch (b_1) {
                c = 1 + c, b_1 && (b_1[(c = c + 1) + (b + 1 - .1 - .1 - .1)] += (("a" || 3) ^ "b" * "foo") != -5 / "number" % (c_2_1 && (c_2_1[(c = 1 + c, 
                c_2_1 = ([] - 23..toString() ^ [ , 0 ][1] >>> "undefined") / (c = c + 1, /[a2][^e]+$/ == "b"))] = 0 & 5)));
                c = 1 + c, (c = c + 1, "undefined" > 22) <= (b_1 && (b_1.var += (-2 ^ "") != "b" <= -4));
            } finally {
                c = 1 + c, c_2_1 && (c_2_1[a++ + []] = ("bar" >> "foo" != ("number" !== -5)) << ((24..toString(), 
                0) >= ("number" > undefined)));
                c = 1 + c, -2 / 4 !== ([ , 0 ].length === 2 ^ 1) ^ (5 >= {}) % (false / "bar");
            }
        }
    }
    var a_2 = f2(a++ + !function a_2() {
        {
            var expr34 = (c = 1 + c, (-3 <= 5) % (0 <= -5) >> (a_2 = 25 ^ "b") + ([ , 0 ].length === 2) % -3);
            for (var key34 in expr34) {
                c = c + 1;
            }
        }
        L16064: for (var brake36 = 5; a_2 && brake36 > 0; --brake36) {
            c = 1 + c, 3 | 0 || undefined === "a" || ("c" !== "number") + (-3 >> "b");
        }
        var undefined_1 = (c = c + 1) + (a_2 && a_2[(c = 1 + c, -1 + -5 === ({} || -5) !== (("a" && "") ^ Infinity + {}))]);
    }());
    function f3(b_1, a_1) {
        {
            for (var brake40 = 5; typeof a_2 == "function" && --_calls_ >= 0 && a_2() && brake40 > 0; --brake40) {
                switch (c = 1 + c, 5 << /[a2][^e]+$/ !== NaN > "object" !== /[a2][^e]+$/ / "object" < ([] | [])) {
                  case c = 1 + c, (-4 === []) >> ("function" || 2) !== (NaN == 5) >> (24..toString() <= "a"):
                    ;
                    break;

                  default:
                    ;

                  case c = 1 + c, undefined >>> -4 == (0 || 2) || ~NaN >>> (-3 << ""):
                    ;
                    break;

                  case c = 1 + c, +("undefined" / undefined) ^ (c_2 = -3 - -2 - ([ , 0 ].length === 2 !== true)):
                    ;
                    break;
                }
            }
            {
                var expr42 = a++ + {
                    0: (c = 1 + c, c_2 && (c_2.var += (23..toString() % 25 == (Infinity, "b")) - (~25 & (4 ^ 24..toString())))),
                    in: (c = 1 + c, 4 / 2 >= (true >= null) !== (-1 == this) + (24..toString() === NaN)),
                    set var(foo) {
                        this.Infinity *= -1 << -1;
                    }
                }[(c = 1 + c, ((-0 <= false) >>> 0 - null) * ((a_2 = "function" || Infinity) * (a_2 && (a_2[(c = 1 + c, 
                (({} == NaN) >= (b_1 += {} || 22)) % (-1 > /[a2][^e]+$/ > 1 % "foo"))] = -3 && 25))))];
                for (var key42 in expr42) {
                    c = 1 + c;
                    var a_2 = expr42[key42];
                    break;
                }
            }
        }
        c = c + 1;
    }
    var b = f3(void (((undefined >>> "bar") + (c = c + 1, NaN)) * (0 > undefined ^ NaN >> -1)));
    function f4(a, b_2, a_2_2) {
        {
            var brake45 = 5;
            do {
                ("b" <= true === (b_2 && (b_2[(c = 1 + c, (("foo" >= 24..toString()) + ("bar" >> 22)) % ("bar" > -1 != ([ , 0 ][1] != 1)))] += null ^ false))) > ("bar" >= null === -2 / "b");
            } while ((c = c + 1) + {
                foo: --b + a_2,
                "\t": b--,
                "\t": (c = c + 1) + +("a" * 24..toString() ^ (a_2 && (a_2[(c = 1 + c, (c = c + 1, 
                "function") / ("b" - 4) >>> (0 === "bar" && 4 ^ /[a2][^e]+$/))] = "" > 3))),
                a: a++ + (("object" >>> [ , 0 ][1]) * (-2 - 2) >= (undefined ^ 23..toString()) * ("bar" - undefined)),
                3: 1 === 1 ? a : b
            }.null && --brake45 > 0);
        }
        if (a_2) {
            return b++;
        } else {
            L16065: {}
        }
    }
    var b_1 = f4("c", /[abc4]/.test((--b + (c = c + 1, (a_2 = 3 ^ -4) & (a_2 && (a_2.foo >>>= "b" && []))) || b || 5).toString()));
    function f5(b_1, bar, a_2_2) {
        c = c + 1;
        var a_2_2 = !function Math() {
            if (c = 1 + c, ([ , 0 ][1] < /[a2][^e]+$/) * ~{} - (Infinity, [ , 0 ].length === 2) / (-2 >>> "undefined")) {
                c = 1 + c, /[a2][^e]+$/ <= 5 === +"" !== (3 <= "a" == (0 && NaN));
            }
        }(), bar_2 = b_1 && b_1.a;
    }
    var bar_2 = f5(a++ + b_1, "a", false);
}

var b_1 = f0();

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

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

function f0(f) {
    var i = function(r, t, o) {
        if (a++, t *= 0, a++ + a++) {
            var e = !(!0 + (!1 | (i && (i.NaN = null))));
            for (var n in e) {
                var i = e[n];
                c = 1 + (c = 1 + c), c = 1 + (c += 1), t && (t[!((t && (t.in = !0)) >>> 0)] += NaN == !0 >> (c += 1, 
                "a"));
            }
        } else {
            switch ("string" != typeof foo_1) {
              case a++ + /[abc4]/.test((a++ + {
                    c: (c = 1 + c, !1 << (38 == (c += 1, 0))),
                    length: (c = 1 + c, c += 1, -3),
                    undefined: (c = 1 + c, !0),
                    NaN: (c = 1 + c, o),
                    3: (c = 1 + c, -25)
                }[(c = 1 + c, 0 == 0 * (t = !1))] || f || 5).toString()):
                c += 1;
                break;

              case (c += 1) + i:
                break;

              case o:
                try {
                    c = 1 + c;
                } finally {}
                break;

              case --f + (i && (i.var = !0), i && (i[(c = 1 + c, !1)] += NaN), void (i &= 0 <= (this == {}))):
            }
        }
    }(0, -1, void 0);
    function s(a, r) {
        for (var t = 5; r && (r[(c = 1 + c, 0)] += 0), (c += 1) + {
            foo: --f - 1,
            "\t": f--,
            "\t": (c += 1) + +(NaN ^ ((-1)[(c = 1 + c, c += 1, 0)] = !1)),
            a: a++ + !1,
            3: a
        }.null && 0 < --t; ) {}
        return f++;
    }
    !function(r) {
        for (var t = 5; c += 1, a-- && r && r.null, [][a++ + (0 <= --_calls_ && s((c = 1 + c, 
        !0), (c = 1 + c, 0 !== (0 == (r && (r.NaN = !0))))))] && 0 < --t; ) {}
        switch (a++ - 0) {
          case (c += 1) + (f = a):
            break;

          case (c += 1) + ("function" == typeof f0 && 0 <= --_calls_ && f0("foo")):
            var o = a;
            for (var e in o) {
                c = 1 + c, r = o[e];
                for (var n = 5; c = 1 + c, c += 1, !0 | (i = 3) <= 0 && 0 < --n; ) {
                    c = 1 + c, c += 1;
                }
            }
            --f, delete f;
            break;

          case f = a:
            break;

          case /[abc4]/.test(((c += 1) + (/[abc4]/.test((c = 1 + c, f || 5).toString()) || a || 3).toString() || f || 5).toString()):
            switch ((c += 1) + void 0) {
              case --f - f:
                c = 1 + c, i && (i[--f + ((c += 1) + ("" + (c = 1 + c, 0 + ((r += !0) || "function") || 4))[(c = 1 + c, 
                1)] || a || 3).toString()] = 1);
                break;

              case f:
                c = 1 + c, c = 1 + (c += 1), r && (r[(c += 1) + [ (c = 1 + c, -4 >>> this === !1 != (-4 ^ (c += 1, 
                -0))), (c = 1 + c, !1), (c = 1 + c, -3 != (!0 & (c += 1, "bar"))), (c = 1 + c, -1 <= 0 % (r && (r.foo = "b"))), (c = 1 + c, 
                (i && (i[f--] /= "38" ^ (i && (i.var += !1)))) / !1) ][(c += 1) + 0]] += !1 / (c += 1, 
                !0));
                break;

              case --f + i:
                c = 1 + (c = 1 + c), c += 1, c += 1, c += 1;
                break;

              case --f + [ (c = 1 + c, !0), (c = 1 + c, i >>= (r && (r.c = 0)) >= (!1 !== (r && (r[(c = 1 + c, 
                0)] = "b")))) ]:
                c = 1 + c, r && (r[[]] = 1);
            }
            c = 1 + c, r && (r[a++ + []] = 2), c = 1 + c;
        }
    }(a++ + !function a() {
        var r = (c = 1 + c, NaN >> 1 + (a = 25));
        for (var t in r) {
            c += 1;
        }
        for (var o = 5; a && 0 < o; --o) {
            c = 1 + c;
        }
        c += 1, a && (c = 1 + c);
    }()), f = function(r) {
        for (var t = 5; "function" == typeof n && 0 <= --_calls_ && n() && 0 < t; --t) {
            switch (c = 1 + c, !0) {
              case c = 1 + c, !1:
                break;

              default:
              case c = 1 + c, 7:
              case c = 1 + c, NaN ^ (i = -1):
            }
        }
        var o = a++ + {
            0: (c = 1 + c, i && (i.var += -4)),
            in: (c = 1 + c, !0 !== (-1 == this) + !1),
            set var(c) {
                this.Infinity *= -1 << -1;
            }
        }[(c = 1 + c, (n = "function") * (n && (n[(c = 1 + c, ((r += {}) <= !1) % !1)] = 25)) * 1)];
        for (var e in o) {
            c = 1 + c;
            var n = o[e];
            break;
        }
        c += 1;
    }(void (c += 1)), s("c", /[abc4]/.test((--f + (c += 1, -1 & ((-1).foo >>>= [])) || f || 5).toString())), 
    a++, c = 1 + (c = 1 + (c += 1));
}

var b_1 = f0();

console.log(null, a, b, c, 1 / 0, NaN, void 0);

original result:
null 142 10 187 Infinity NaN undefined

uglified result:
null 142 10 197 Infinity NaN undefined

minify(options):
{
  "compress": {
    "keep_fargs": false,
    "passes": 1000000,
    "sequences": 1000000,
    "unsafe": true,
    "unsafe_Function": true,
    "unsafe_math": true,
    "unsafe_proto": true,
    "unsafe_regexp": true
  }
}

Suspicious compress options:
  evaluate
  passes
  reduce_vars