strip: extract code to create strip backup We will reuse this for soft stripping.

strip: clarify comment around bundle create We may create two bundles, one for the changeset actually stripped, and one for the changeset affected by the strip we want to keep. (Changesets with a higher rev number than the striped ones). For soft stripping, we still need to the first one (used for "restoring" the changesets), but not the second one. We start with clarifying which bits of the code is used for what.

strip: move attributes shortcut assigned earlier This series will add support for "soft" stripping using the archived phase in addition to the usual heavy weight revlog stripping. First, we need to refactor the strip function to extract logic common to the "soft-strip" case. We are about to extract bits of the strip function into separate functions. Those blocks of code contain variables for frequently accessed attributes. We move those variables outside of the soon to be moved blocks.

log: fix line wrap on diffstat with -G/--graph (issue5800) Differential Revision: https://phab.mercurial-scm.org/D5485

registrar: minor cleanup to the merge function Pointed out by Yuya.

vfs: raise NotImplementedError in abstractvfs._auditvfs This make sure that auditing is implemented.

vfs: handle _auditpath in proxyvfs Just forward the call to the underlying vfs.

vfs: fix proxyvfs inheritance The proxyvfs class is designed to overwrite some of the vfs logic. Yet, it did not use normal class inheritance. This is becoming an issue as `abstractvfs` method could take precedence over their `proxyvfs` version. We fix the inheritance chain to be as expected.

vfs: also audit rename Renaming through the vfs is not used in many places, and none of them seems to be a security risk. However, it is still worthwhile to run the auditing on rename file to perform developer-warning level checks.

vfs: add a `_auditpath` to abstract vfs We are about to make `rename` audit path. Since rename lives in the `abstractvfs` layer, we need it to be aware of auditing to some extent. The default implementation is no-op because multiple existing vfs are not using auditing at all right now (eg: fncachevfs).

vfs: makes all audited path relative Only auditing relative path helps the vfs warning logic.

debugupgraderepo: add a --no-backup mode The process has been around for a while and is pretty safe now. Having an automated way to clean up the old data is useful when running many different conversion to compare delta algorithm.

upgrade: add '-' in optimization name The older name `redeltaall` was hard to type and read. The newer form should be more user-friendly. We keep backward compatibility with the old form (at least for a while). Having to use different form depending on the version is very impractical and error prone.

revlog: add test case for _findsnapshots Testing the method directly is more robust.

revlog: use the native implementation of issnapshot In some sparserevlog case where a lot of the history has to be searched for a snapshot, the cost of issnashot cost becomes significant. The computation done by the method is fairly low level, a native implementation provide a very significant speedup. example affected manifest write before: 0.490375s after: 0.114989s (-76%)

revlog: add a native implementation of issnapshot This will be used in the next changesets