Angular hard limit recursion in equals()

angular-equals.js

var currentEqualsLevel = 0;
var maxEqualsLevel = 10;

function equals(o1, o2) {

  if (currentEqualsLevel>=maxEqualsLevel)
    return true; // we consider objects equal to this level

  if (o1 === o2) return true;
  if (o1 === null || o2 === null) return false;
  if (o1 !== o1 && o2 !== o2) return true; // NaN === NaN
  var t1 = typeof o1, t2 = typeof o2, length, key, keySet;
  if (t1 == t2) {
    if (t1 == 'object') {
      if (isArray(o1)) {
        if (!isArray(o2)) return false;
        if ((length = o1.length) == o2.length) {
          for (key = 0; key < length; key++) {
              try {
                  currentEqualsLevel++;
                  if (!equals(o1[key], o2[key])) return false;
              } finally {
                  currentEqualsLevel--;
              }
          }
          return true;
        }
      } else if (isDate(o1)) {
        if (!isDate(o2)) return false;
          try {
              currentEqualsLevel++;
              return equals(o1.getTime(), o2.getTime());
          } finally {
              currentEqualsLevel--;
          }
      } else if (isRegExp(o1)) {
        return isRegExp(o2) ? o1.toString() == o2.toString() : false;
      } else {
        if (isScope(o1) || isScope(o2) || isWindow(o1) || isWindow(o2) ||
          isArray(o2) || isDate(o2) || isRegExp(o2)) return false;
        keySet = {};
        for (key in o1) {
          if (key.charAt(0) === '$' || isFunction(o1[key])) continue;
            try {
                currentEqualsLevel++;
                if (!equals(o1[key], o2[key])) return false;
            } finally {
                currentEqualsLevel--;
            }
          keySet[key] = true;
        }
        for (key in o2) {
          if (!keySet.hasOwnProperty(key) &&
              key.charAt(0) !== '$' &&
              o2[key] !== undefined &&
              !isFunction(o2[key])) return false;
        }
        return true;
      }
    }
  }
  return false;
}