I'm currently at war with Magnar, playing Altar, and conquered his capitol and another city. A couple turns later I noticed Magnar himself moving towards his old capitol. As I didn't have any troops in the area I was expecting to loose the city again. Instead of getting notified that I lost the city, however, the battle window popped up, asking me to select either auto-resolve or tactical battle. The city still had militia, which where able to defeat Magnar.

The changelog for 0.915 states that if you conquer a city you haven't founded yourself, it won't have any natural defenders. Has this change been dropped or is it a bug?