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

revlog: more efficient implementation for issnapshot We avoid multiple method calls and tuple creation, this provides a significant speedup in some case: example affected manifest write before: 0.815520s after: 0.487767s (-40%)

revlog: clarify the non sparse-revlog case in `issnapshot` If we are not using sparse-revlog, there is only one type of snapshot, the full one.

exthelper: switch to using the registrar merging method

registrar: add a method to merge registrar instances This provides sanity checking beyond simply merging the underlying dictionaries.

phabricator: ensure that the return of urlopener.open() is closed No problem observed, just an oversight noticed while reading documentation.

revlog: fix pure python slicing test when chain contains nullrev The revlog mock used in the test was not behaving the same as its C counterpart.

merge with stable

remotefilelog: fix bug in maybesparsematch returning alwaysmatcher The description of the method says that it should return None if sparse is not used in this repository; since sparse.matcher() returns alwaysmatcher if sparse is not enabled, I'm using that as the signal to return None here to preserve the previous behavior. Differential Revision: https://phab.mercurial-scm.org/D5487

procutil: correct spelling of uninterruptable -> uninterruptible Differential Revision: https://phab.mercurial-scm.org/D5488

help: show advanced, experimental and deprecated extensions with --verbose I noticed that phabricator and absorb weren't showing up, no matter what. There's a related problem where commands for these extensions *do* show up without --verbose. I'm not sure what the point of hiding the extensions, but not the commands is.

help: remove a duplicate category name entry for TOPIC_CATEGORY_NONE

phabricator: assign commands to help categories `phabsend` and `phabupdate` seem pretty close to `email`. `phabread` is a little less close, but can be trivially used to actually import patches.

largefiles: eliminate an unnecessary import of configitems Thanks to Yuya for pointing this out.

exthelper: add some examples for using registrar aliases Maybe it's my general lack of python knowledge, but how to use these would be way too obscure for me otherwise.