copies: use intersectmatchers() in non-merge p1 optimization
This enables the optimization introduced by d4247c306d82 for non-rebase cases.
Before, the match couldn't be narrowed if it was e.g. alwaysmatcher.
The logic is copied from bd56bea5ecf8.
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.