If a person started out making Kiddush on a revi’is of wine, but it spilled in the process of making Kiddush and now he has less than a revi’is in the cup, is he still yotzi?
Does it make a difference at what point it spilled and became less than a revi’is?
As long as the bottle of wine is in front of him on the table, he should refill the up and continue on with kiddush. The bracha on the wine as well as the bracha of kiddush still remains valid.
see Shulchan Aruch O:C 271:15 and the MIshna Brura there.