Uglify error sample

sample.js

var input = Array.from([17, 240, 159, 152, 128, 32]);

function utf8_read(buffer, start, end) {
    var len = end - start;
    if (len < 1)
        return "";
    var parts = null,
        chunk = [],
        i = 0, // char offset
        t;     // temporary
    while (start < end) {
        t = buffer[start++];
        if (t < 128)
            chunk[i++] = t;
        else if (t > 191 && t < 224)
            chunk[i++] = (t & 31) << 6 | buffer[start++] & 63;
        else if (t > 239 && t < 365) {
            t = ((t & 7) << 18 | (buffer[start++] & 63) << 12 | (buffer[start++] & 63) << 6 | buffer[start++] & 63) - 0x10000;
            chunk[i++] = 0xD800 + (t >> 10);
            chunk[i++] = 0xDC00 + (t & 1023);
        } else
            chunk[i++] = (t & 15) << 12 | (buffer[start++] & 63) << 6 | buffer[start++] & 63;
        if (i > 8191) {
            (parts || (parts = [])).push(String.fromCharCode.apply(String, chunk));
            i = 0;
        }
    }
    if (parts) {
        if (i)
            parts.push(String.fromCharCode.apply(String, chunk.slice(0, i)));
        return parts.join("");
    }
    console.log(chunk);
    return String.fromCharCode.apply(String, chunk.slice(0, i));
};

function utf8_read_min(t, e, n) {
    if (n - e < 1)
        return "";
    for (var r, i = null, o = [], s = 0; e < n; )
        r = t[e++],
            o[s++] = r < 128 ? r : 191 < r && r < 224 ? (31 & r) << 6 | 63 & t[e++] : 239 < r && r < 365 ? (r = ((7 & r) << 18 | (63 & t[e++]) << 12 | (63 & t[e++]) << 6 | 63 & t[e++]) - 65536,
                o[s++] = 55296 + (r >> 10),
            56320 + (1023 & r)) : (15 & r) << 12 | (63 & t[e++]) << 6 | 63 & t[e++],
        8191 < s && ((i || (i = [])).push(String.fromCharCode.apply(String, o)),
            s = 0);
    console.log(o);
    return i ? (s && i.push(String.fromCharCode.apply(String, o.slice(0, s))),
        i.join("")) : String.fromCharCode.apply(String, o.slice(0, s))
};

utf8_read(input, 0, input.length);

utf8_read_min(input, 0, input.length);