compat: drop the context manager used to write the cache file Mercurial 3.8 does not supports context manager on atomic temporary file.

compat: make obscache code compatible with Mercurial version prior to 4.2 the phasecache.getrevset method is new in 4.2.

evolve: record testing with 4.2 4.2 is now a things and tests pass fine.

merge with default for 6.1.0

packaging first step toward 6.1.0

auto-push: move config help in the extension help That is a better spot than the extension itself.

opening mercurial 4.1 compat branch This branch will receive test update implied by the 4.2 → 4.1 changes.

obscache: skip writing to disk if the data did not changed This will avoid rewriting the cache for every single transaction.

obscache: skip writing if the cache is empty if the cache is empty, we can just skip writing to disk.

obscache: set a valid "empty" cache key if the cache is missing This avoid detecting bad cache when it just happens to be no cache.

obscache: have the obsstore fix empty file cachekey Before this change, the missing file and empty file returned different value.

obscache: log case where the cache is not up to date This will help track performance issue

obscache: still update and use the cache during transaction Other code might access the obsolete set in the middle of a transaction. It is better to use the case in that case since the update will eventually be written when the transaction is committed.

obscache: warm the cache in all cases There are case when the obsstore have been invalidated, but we still need to update the cache.

obscache: update the format to allow negative tiprev If the changelog is empty (but the obsstore is not) the 'tiprev' will be -1.

obscache: load the disk data before checking is the cache is up to date This is actually required since non-loaded cache will never be up to date...