Is a demurrer moot if there is an amended complaint on file that supersede the original pleading?

Appellant raises one argument on appeal. He contends the trial court erred in sustaining respondent's demurrer to his original complaint because there was an amended complaint on file prior to the hearing on the demurrer. Appellant thus reasons that, pursuant to Code of Civil Procedure section 472, his amended complaint superseded the original complaint as the "active" pleading in the case, rendering the demurrer moot.² (See People ex rel. Strathmann v. Acacia Research Corp. (2012) 210 Cal.App.4th 487, 506 [" 'The filing of the first amended complaint render[s] [the defendant]'s demurrer moot since " 'an amendatory pleading supersedes the original one, which ceases to perform any function as a pleading' " ' "].)