merge: never do premerge on symlinks Simplemerge is not symlink aware and will never do the right thing on symlinks.

merge: make internal merge fail cleanly on symlinks Simplemerge is not symlink aware and will never do the the right thing on symlinks. It would read the symlink as a file and abort with 'No such file or directory' on dangling symlinks. Instead, internal:merge now simply fails to merge symlinks.

debugpushkey: list keys sorted

debugdiscovery: report heads in sorted order

hidden: drop of the repo.hiddenrevs property It does not have any user left

context: retrieve hidden from filteredrevs This prepare the dropping of the repo.hiddenrevs property

revset: retrieve hidden from filteredrevs This prepare the dropping of the `repo.hiddenrevs` property

hidden: use both parents of working directory If we are merging with and extinct revision, this extinct revision should not be hidden.

hidden: drop cache on hiddenrevs property The `filteredrevs` function already have a cache mechanism. And this cache in invalidated at the same time than the current property cache. So we drop the cache on the property. The property itself is going to be dropped soon.

hidden: move computation in filter function There is not good reason for this computation to be handle in a different way from the other. We are moving the computation of hidden revs in the filter function. In later changesets, code that access to `repo.hiddenrevs` will be updated and the property dropped.

branchcache: add note about cache invalidation to test-keyword.t [Should've been included in aff706b3a21c.] --Kevin Bullock <kbullock@ringworld.org>

clfilter: add impactable filter The `mutable` filter still have some chance to get invalidated. This will happen when: - you garbage collect hidden changeset, - public phase is moved backward, - something is changed in the filtering (this could be fixed) So we introduce an even more stable filtering set: everything with a revision number egal or higher than the first mutable changeset is filtered. The only official use of this filter is for branchcache.

clfilter: add mutable filtering It filters all mutable changesets, leaving only public changeset unfiltered. This filtering set is expected to be much more stable that the previous one as public changeset are unlikely to disapear. The only official use of this filter is for branchcache.

run-tests.py: fix handling of symlink to the right python Before: a symlink for python in BINDIR was sometimes created, but it was never updated when a different Python was used and it was never removed. An invalid python could thus be left around and used when testing with --local. Now: the symlink is removed when wrong and created when necessary. The mechanism for finding the right name (python or python.exe) also had to be simplified and made more explicit.

log: use "hidden" filtering instead of manual check at display time When log is not given the --hidden option, hidden revision are not shown. We move the implementation from manual checking at display time to changelog filtering. This is the first official usage of the hidden filtering.

clfilter: introduces a hidden filter This filter exclude all hidden revision. We plan to use this filter to hide revision instead of manually checking contents of the hidden revisions set.

perftest: allow selection of volatile set to benchmark This helps when you focus on a subset of the volatile chain.

perftest: add a command to benchmark construction of volatile cache Obsolescence and filtering related caches are critical. Having a handy way to check them is valuable.

perftest: add an option to invalidate volatile cache Some revsets are sensitive to such initialization. Being able to test the impact is great.

perftest: document the perfrevset command I'll add an argument to it.

perftest: migrate to new style command declaration Declaring synopsis and argument on the function site is much clearer.

perftest: drop duplicated codes The `perfnodelookup` lookup commands is duplicated. We drop the first version, overwritten by the seconds.

cmdutil: make options argument optional There is not reason to force passing of an empty options list.

branchmap: allow to use cache of subset Filtered repository are *subset* of unfiltered repository. This means that a filtered branchmap could be use to compute the unfiltered version. And filtered version happen to be subset of each other: - "all() - unserved()" is a subset of "all() - hidden()" - "all() - hidden()" is a subset of "all()" This means that branchmap with "unfiltered" filter can be used as a base for "hidden" branchmap that itself could be used as a base for unfiltered branchmap. unserved < hidden < None This changeset implements this mechanism. If the on disk branchcache is not valid we use the branchcache of the nearest subset as base instead of computing it from scratch. Such fallback can be cascaded multiple time is necessary. Note that both "hidden" and "unserved" set are a bit volatile. We will add more stable filtering in next changesets. This changeset enables collaboration between no filtering and "unserved" filtering. Fixing performance regression introduced by 47f00b0de337