relnotes/5.3

match: strengthen visit_children_set invariant, Recursive means "all files"

My previous interpretation of "Recursive" was too relaxed: I thought it
instructed the caller to do something like this:

> you can stop calling `visit_children_set` because you'll need to descend into
> every directory recursively, but you should still check every file if it
> matches or not

Whereas the real instruction seems to be:

> I guarantee that everything in this subtree matches, you can stop
> querying the matcher for all files and dirs altogether.

The evidence to support this:

- the test actually passes with the stronger invariant, revealing no
exceptions from this rule

- the implementation of `visit_children_set` for `DifferenceMatcher`
clearly relies on this requirement, so it must hold for that not to
lead to bugs.

== 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).