bundlerepo: apply phase data stored in the bundle instead of assuming `draft` The phase information contained in the changegroup part and the explicit `phase-heads` part are now taken in account. Initial changes and test by Matt Harbison, code rework by Pierre-Yves David.

bundlerepo: handle changegroup induced phase movement in the associated method These movement comes from handling the changegroup part, so we keeps the code grouped. This will be important when handling more part (and more changegroup part in the future) This induce a small code duplication, but it does not looks terrible.

bundlerepo: move most attribute declaration earlier in __init__ The expected attribute are clearer this way. The bundle handling code is responsible for setting most of it.

bundlerepo: move the handling of bundl1 in its own method This should make the overall flow simpler to follow.

bundlerepo: expliclty handing cg part from bundle2 We will handle other types of parts soon (phase-heads) so we need some cleanup first.

transaction: use the standard transaction mechanism to backup branch Branch is a bit special : - It currently does not collaborate with the transaction (or any scoping) for writing (this is bad) - It can change without the lock being taken (it is protected by `wlock`) So we rely on the same mechanism as for the backup of the other dirstate file: - we only do a backup if we hold the wlock - we force a backup though the transaction Since "branch" write does not collaborate with the transaction, we cannot back it up "at the last minute" as we do for the dirstate. We have to back it up "upfront". Since we have a backup, the transaction is no longer doing its "quick_abort" and get noisy. Which is quite annoying. To work around this, and to avoid jumping in yet-another-rabbit-hole of "getting branch written properly", I am doing horrible things to the transaction in the meantime. We should be able to get this code go away during the next cycle. In the meantime, I prefer to take this small stop so that we stop abusing the "journal" and "undo" mechanism instead of the proper backup mechanism of the transaction. Also note that this change regress the warning message for the legacy fallback introduced in 2008 when issue902 got fixed in dd5a501cb97f (Mercurial 1.0). I feel like this is fine as issue 902 remains fixed, and this would only affect people deploying a mix of 15 year old Mercurial and modern mercurial, and using branch and rollback extensively.

transaction: no longer explicitly cache bookmarks The transaction file generation is already dealing with the backup for this. So, no need to duplicate such backup.