branchcache: add a "pure topological head" fast path
In a narrow but actually quick common case, all topological heads are all on
the same branch and all open. In this case, computing the branch map is very
simple. We can quickly detect situation where this situation will not change.
So we update the V3 format to be able to express this situation and upgrade the
update code to detect we remains in that mode.
The branch cache is populated with the actual value when the branch map is
accessed, but the update_disk method can do the update without needing to
populate it.
== New Features ==
* Windows will process hgrc files in %PROGRAMDATA%\Mercurial\hgrc.d.
== New Experimental Features ==
== Bug Fixes ==
* The `indent()` template function was documented to not indent empty lines,
but it still indented the first line even if it was empty. It no longer does
that.
== Backwards Compatibility Changes ==
== Internal API Changes ==
* Matcher instances no longer have a `explicitdir` property. Consider
rewriting your code to use `repo.wvfs.isdir()` and/or
`ctx.hasdir()` instead. Also, the `traversedir` property is now
also called when only `explicitdir` used to be called. That may
mean that you can simply remove the use of `explicitdir` if you
were already using `traversedir`.
* The `revlog.nodemap` object have been merged into the `revlog.index` object.
* `n in revlog.nodemap` becomes `revlog.index.has_node(n)`,
* `revlog.nodemap[n]` becomes `revlog.index.rev(n)`,
* `revlog.nodemap.get(n)` becomes `revlog.index.get_rev(n)`.
* `copies.duplicatecopies()` was renamed to
`copies.graftcopies()`. Its arguments changed from revision numbers
to context objects. It also lost its `repo` and `skip` arguments
(they should no longer be needed).