What is the test for an increase in the maximum sentence for a criminal conviction where the crime was committed prior to the criminal conviction?

(iv) Finally, in People v. Venegas (1970) 10 Cal.App.3d 814, 89 Cal.Rptr. 103 (a case concerning the applicability of an increase in the maximum sentence for a "felon in possession" conviction, where the increase had been legislatively adopted after the prior felony had been committed), the court stated: "Section 12021, as amended in 1965, was on the books for years prior to defendant's violation of section 12021 on March 12, 1969, and for which he was convicted. A statute is not retroactive in operation merely because it draws upon facts antecedent to its enactment for its operation. [Citation.]" (10 Cal.App.3d at p. 823, 89 Cal.Rptr. 103.) Venegas is somewhat different in principle than the above cases; however, it dealt only with the applicability of an increase in a penalty for the commission of a subsequent crime, the commission of which crime was a given.