Someone should publish a pamphlet that outlines differences in laws and it should be distributed at Concealed Carry Permit classes. There have been several threads on this same problem lately.
The Concealed Carry Permit classes should hammer into the heads of their students that they need to know the current laws of any state or city they plan to visit.
The pamphlet would be good the day it was sent to the publisher, if it was correct.
Gun laws and reciprocity are changing all the time.
Your best bet is to check the NRA website for current conditions before traveling with a weapon.