Where is the Unreachable Code?

[Mittineague]

The Firefox Developer Editions dev tool JavaScript console is giving me

SyntaxError: unreachable code after return statement

for this code (deminified by me for easier reading)

eval("/*!
 * jQuery Cookie Plugin
 * https://github.com/carhartl/jquery-cookie
 *
 * Copyright 2011, Klaus Hartl
 * Dual licensed under the MIT or GPL Version 2 licenses.
 * http://www.opensource.org/licenses/mit-license.php
 * http://www.opensource.org/licenses/GPL-2.0
 */

(function($) {
    $.cookie = function(key, value, options) {

        // key and at least value given, set cookie...
        if (arguments.length > 1 && (!/Object/.test(Object.prototype.toString.call(value)) || value === null || value === undefined)) {
            options = $.extend({}, options);

            if (value === null || value === undefined) {
                options.expires = -1;
            }

            if (typeof options.expires === 'number') {
                var days = options.expires, t = options.expires = new Date();
                t.setDate(t.getDate() + days);
            }

            value = String(value);
            return (document.cookie = [
                encodeURIComponent(key), '=', options.raw ? value : encodeURIComponent(value),
                options.expires ? '; expires=' + options.expires.toUTCString() : '', // use expires attribute, max-age is not supported by IE
                options.path    ? '; path=' + options.path : '',
                options.domain  ? '; domain=' + options.domain : '',
                options.secure  ? '; secure' : ''
            ].join(''));
        }

        // key and possibly options given, get cookie...
        options = value || {};
        var decode = options.raw ? function(s) { return s; } : decodeURIComponent;

        var pairs = document.cookie.split('; ');
        for (var i = 0, pair; pair = pairs[i] && pairs[i].split('='); i++) {
            if (decode(pair[0]) === key) return decode(pair[1] || ''); // IE saves cookies with empty string as \"c; \", e.g. without \"=\" as opposed to EOMB, thus pair[1] may be undefined
        }
        return null;
    };
})(jQuery);
" + "
//# sourceURL=jquery.cookie");

As far as I can see, all of the returns are in if if blocks or ternary ifs, and I don’t see any that will necessarily always return, so what is unreachable? Am I not seeing something? Is the console pranking me?

[felgall]

Sticking the code into jsbin reports the following as the first error:

Line 42: Expected a conditional expression and instead saw an assignment.

after getting rid of the eval( off the front.

[Mittineague]

ha, I was looking at the "return"s for the culprit and missed seeing
for (var i = 0, pair; pair = pairs[i] && pairs[i].split('='); i++) {

So the code chokes at pair = pairs[i] && pairs[i].split('=') because pairs[i] might be a boolean but split returns an array or empty string?

Odd that this would go unnoticed since 2011