- Make my read-marker experiments backwards-compatible, by introducing a
new artificial marker
- Fix sometimes the marker going missing, by not deduplicating read
markers, then filtering out the other one because duplicates didn't
respect the thread id
Needs an initial sync to fully apply.
Change-Id: Id02ae19d03077016cbeb8d9a8fd5130d77931b2d
a48ce4b18c