Yesterday I said "shabbat shalom" to someone and he said we don't do that on Tisha b'Av that falls on Shabbat. I thought that Shabbat trumps the day (and that's why we move the other observances). ...
When Tisha B'Av comes out on a Shabbos, do we say Pirkei Avos in the cycle on that Shabbos?
We have a tradition that Tisha B'Av will become a holiday in the time of Moshiach. Will that holiday also be nidcheh if it comes out on Shabbos?
When 9 be-Av falls on Shabbos, it is moved to the following Sunday. Are there any restrictions on Shabbos because of 9 be-Av (maybe tashmish is forbidden)?