California Insurance Code 170-172

170. Unless the policy otherwise provides, if a mortgagor of property effects insurance in his own name providing that the loss shall be payable to the mortgagee, or assigns a policy of insurance to a mortgagee, the insurance is deemed to be upon the interest of the mortgagor and the mortgagor does not cease to be a party to the original contract. 171. In case of such a provision or assignment, any act of the mortgagor, prior to the loss and which would otherwise avoid the insurance, will have the same effect, although the property is in the hands of the mortgagee; but any act which, under the contract of insurance, is to be performed by the mortgagor, may be performed by the mortgagee therein named, with the same effect as if it had been performed by the mortgagor. 172. If an insurer assents to the transfer of insurance from a mortgagor to a mortgagee, and, at the time of the assent, imposes further obligations on the assignee, the acts of the mortgagor cannot affect the rights of the assignee.