Simple bug, should be reproduceable, what happened is, i attacked an NPC which i had a demand on one of its cities on, and won the war.

The demand was Autofullfilled(dont know if this can happen if its not a demand) though the city was still under siege by a friend fighting the same npc. 

Now im stuck with a city i cannot reclaim, but costs me influence due to the citycap, due to my friend not being at war with me.

Maybe besieged cities should either be removed from being able to be taken or the siege should end on war resolution!