copyfiles: deal with existing file when hardlinking
If the hardlinking fails, we fallback to `shutil.copy`, but do not consider
future hardlinking doomed.
This is a slight improvement from the current situation, we still avoid
hardliking in a case we might be able to do it. However this does not have an
impact of the rest of the operation.
(This is an opportunity improvement while looking at something next to that.)
Differential Revision: https://phab.mercurial-scm.org/D10841
Mercurial
=========
Mercurial is a fast, easy to use, distributed revision control tool
for software developers.
Basic install::
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
Running without installing::
$ make local # build for inplace usage
$ ./hg --version # should show the latest version
See https://mercurial-scm.org/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.
Notes for packagers
===================
Mercurial ships a copy of the python-zstandard sources. This is used to
provide support for zstd compression and decompression functionality. The
module is not intended to be replaced by the plain python-zstandard nor
is it intended to use a system zstd library. Patches can result in hard
to diagnose errors and are explicitly discouraged as unsupported
configuration.