In what circumstances will the trial court allow a plaintiff to amend a third amended complaint?

In directing the trial court to afford another opportunity to amend, we are not unaware of the limitation on the general rule expressed in Whitson v. City of Long Beach (1962) 200 Cal.App.2d 486, at page 504, 19 Cal.Rptr. 668. Whether, if a third amended complaint is still subject to a general or special demurrer, the trial court should allow a fourth amendment is a matter which we could not, and do not, determine on the record before us. Nothing herein necessarily compels the allowance of more than one further amendment.