(a) As used in this Code section, the term "original party" means, without limitation, any bank, trust company, or other corporation into which the grantee of any real estate mortgage or deed conveying realty as security for a debt shall be merged or consolidated. In addition to the foregoing, the term "original party," as used in this Code section, shall also include, without limitation, any bank, trust company, or other corporation, whether organized and existing under the laws of the United States or this state, into which the grantee of any real estate mortgage or deed conveying realty as security for a debt shall be converted.

(b) Except as provided in subsection (c) of this Code section, the operation of "open-end" clauses contained in real estate mortgages or deeds conveying realty as security for a debt, which clauses provide that, in addition to securing the debt named or described in the instrument, such instruments or the property thereby conveyed shall also secure any other debt or obligation that may be or become owing by the mortgagor or grantor, is limited to other debts or obligations arising ex contractu, as distinguished from those arising ex delicto, between the original parties to the security instrument.

(c) A transferee or assignee of an original party to a home equity line of credit agreement or contract who makes additional advances or disbursements on a home equity line of credit shall have the benefit of the security under the deed if the disbursements, made after the assignment, were authorized by the original parties to the home equity line of credit agreement or contract.