relnotes/5.3

shelve: rewrite check for unknown shelf to delete

The code would try to delete the shelf's .patch file and if that
raised an exception, it would convert it to an `error.Abort`. This
patch rewrites it so the check is done upfront. I find it easier to
read that way. It's now clear enough that I removed the comment
explaining it as well.

As Joerg pointed out during review, another differences is that the
old code would move a `.hg` file without its `.patch` friend to backup
before it realized that the `.patch` file was missing. The new code
will error out earlier and not move the `.hg` file, which seems like
an improvement. That should only matter on corrupt `.hg/shelved/`
directories, however.

Differential Revision: https://phab.mercurial-scm.org/D9697

== 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).