(b) If after the date of the mortgage or deed of trust, any sum of money is advanced or readvanced, any endorsement or guaranty is made, or the liability under an indemnity agreement arises, priority for such sum of money or for any indemnity arising under the endorsement, or guaranty, or indemnity agreement dates from the date of the mortgage or deed of trust as against the rights of intervening purchasers, mortgagees, trustees under deeds of trust, or lien creditors, regardless of whether the advance, readvance, endorsement, or guaranty was obligatory or voluntary under the terms of the mortgage or deed of trust.