This chapter shall not be amended so as to have a material, adverse effect upon the rights of the holders of any outstanding bonds theretofore issued under this chapter, or the rights of participating parties with respect to whom projects have theretofore been financed under this chapter, without the written consent of such bondholders and participating parties; provided, however, that this chapter may amended at any time (a) to make such provisions for the purpose of curing any ambiguity, or of curing, correcting or supplementing any defective provisions contained in this chapter, as the city may deem necessary or desirable; or (b) if such amendment does not materially impair or adversely affect the interests of any such bondholder or participating party in the opinion of the council; or (c) if such amendments apply solely to bonds not theretofore issued under this chapter or participating parties with respect to whom projects have not theretofore been financed under this chapter. (Ord. 1047 (part), 1985)