copies: create helper for getting all copies for changeset There are a few places where we get all the copies for a changeset (at least the {file_copies} template and in two places in `hg log --copies` code). These places currently call scmutil.getrenamedfn() to get a caching "getrenamed" function. They all use it in a similar way. We will be able to reuse more code by having a function for getting all the copies for a changeset. This patch introduces such a function. It uses it in the {file_copies} template to show that it works. It relies on the existing scmutil.getrenamedfn() for caching in the filelog-centric case. Differential Revision: https://phab.mercurial-scm.org/D6545

logcmdutil: also check for copies in null revision and working copy It's safe (and fast) to look for copies in the null revision, and it's incorrect not to look for them in the working copy, so let's look in both places. Differential Revision: https://phab.mercurial-scm.org/D6544

tests: demonstrate missing copy information in working copy with graphlog Differential Revision: https://phab.mercurial-scm.org/D6543

remotefilelog: handle copies in changesets in getrenamedfn() override E.g. the {file_copies} template keyword didn't work with copies in changesets before this patch because remotefilelog overrides the getrenamedfn() and didn't handle the changeset-centric case. Differential Revision: https://phab.mercurial-scm.org/D6542

remotefilelog: check if RFL is enabled in getrenamedfn() override In 8a0e03f7baf4 (remotefilelog: move most setup from onetimesetup() to uisetup(), 2019-05-01), I said: All the wrappers moved in this patch check if remotefilelog is enabled before they change behavior, so it's safe to always wrap. That was clearly a lie, because getrenamedfn() didn't. That made e.g. `hg log -T {file_copies}` unbearably slow. This patch fixes that. Differential Revision: https://phab.mercurial-scm.org/D6541

relnotes: document template support for `hg root` Differential Revision: https://phab.mercurial-scm.org/D6540

remotefilelog: tell runbgcommand to not block on child process startup These two invocations will always find a binary because they're re-running hg. As a result, we can skip waiting for the subprocess to start running and save a little bit of wall-time. Differential Revision: https://phab.mercurial-scm.org/D6539

procutil: allow callers of runbgcommand to assume the process starts Experimentally starting the subprocess can take as much as 40ms, and for some of our use cases that's frivolous: we know the binary will start, and if it doesn't we'd only ever ignore it and continue anyway. This lets those use cases be faster. Differential Revision: https://phab.mercurial-scm.org/D6537

shallowrepo: remove backwards compat code that predates in-tree remotefilelog Differential Revision: https://phab.mercurial-scm.org/D6538

commit: make the error message more specific while aborting branch closing Differential Revision: https://phab.mercurial-scm.org/D6493