commit: factor out empty commit check to `basectx.isempty()`
This enables reuse in other places, e.g. those dealing with `memctx`.
Differential Revision: https://phab.mercurial-scm.org/D8729
== New Features ==
* `hg purge`/`hg clean` can now delete ignored files instead of
untracked files, with the new -i flag.
* `hg pull` now has a `--confirm` flag to prompt before applying changes.
Config option `pull.confirm` is also added for that.
* `hg log` now defaults to using an '%' symbol for commits involved
in unresolved merge conflicts. That includes unresolved conflicts
caused by e.g. `hg update --merge` and `hg graft`. '@' still takes
precedence, so what used to be marked '@' still is.
* New `conflictlocal()` and `conflictother()` revsets return the
commits that are being merged, when there are conflicts. Also works
for conflicts caused by e.g. `hg graft`.
* `hg copy --forget` can be used to unmark a file as copied.
* The `format.revlog-compression` configuration entry now accept a list. The
first available option will be used. for example setting::
[format]
revlog-compression=zstd, zlib
Will use `zstd` compression for new repositories is available, and will
simply fall back to `zlib` if not.
* `hg debugmergestate` output is now templated, which may be useful
e.g. for IDEs that want to help the user resolve merge conflicts.
== New Experimental Features ==
* `hg copy` now supports a `--at-rev` argument to mark files as
copied in the specified commit. It only works with `--after` for
now (i.e., it's only useful for marking files copied using non-hg
`cp` as copied).
* Use `hg copy --forget --at-rev REV` to unmark already committed
copies.
== Bug Fixes ==
* Fix server exception when concurrent pushes delete the same bookmark
* Prevent pushes of divergent bookmarks (foo@remote)
* The push error "remote repository changed while pushing - please
try again" now only happens when a concurrent push changed related
heads (instead of when a concurrent pushed any revision).
== Backwards Compatibility Changes ==
* When `hg rebase` pauses for merge conflict resolution, the working
copy will no longer have the rebased node as a second parent. You
can use the new `conflictparents()` revset for finding the other
parent during a conflict.
* `hg rebase` now accepts repeated `--source` and `--base`
arguments. For example, `hg rebase --source 'A + B'` is equivalent
to `hg rebase --source A --source B`. This is a
backwards-incompatible change because it will break overriding an
alias `myrebase = rebase --source A` by `hg myrebase --source B`
(it will now rebase `(A + B)::` instead of `B::`).
* `hg recover` does not verify the validity of the whole repository
anymore. You can pass `--verify` or call `hg verify` if necessary.
* `hg debugmergestate` output format changed. Let us know if that is
causing you problems and we'll roll it back.
* Resolved merge conflicts are now cleared by `hg commit` even if the
working copy has no changes.
== Internal API Changes ==
* The deprecated `ui.progress()` has now been deleted. Please use
`ui.makeprogress()` instead.
* `hg.merge()` now takes a `ctx` instead of the previous `repo` and
`node` arguments.
* `hg.merge()` has lost its `abort` argument. Please call
`hg.abortmerge()` directly instead.
* `hg.merge()` has lost its `mergeforce` argument. It should have
only ever been called with the same value as the `force` argument.
* The `*others` argument of `cmdutil.check_incompatible_arguments()`
changed from being varargs argument to being a single collection.