commit: clear mergestate also with --amend (issue6304)
The `hg commit --amend` uses the in-memory code, which naturally
doesn't touch the merge state (well, it shouldn't anyway; I think I've
fixed bugs in that area recently). We therefore need to clear the
mergestate after calling `repo.commitctx()` since we expect that from
`hg commit --amend`.
Differential Revision: https://phab.mercurial-scm.org/D8932
== New Features ==
* The amend extension supports the `--currentuser` argument.
* The amend extension supports the `--close-branch` argument.
* The amend extension supports the `--secret` argument.
* The uncommit extension supports the `rewrite.update-timestamp` config option.
== New Experimental Features ==
== Bug Fixes ==
== Backwards Compatibility Changes ==
* A shell that supports `$(command)`` syntax for command substitution is now
required for running the test suite. The test runner normally uses
`sh`, so if that is a shell that doesn't support `$(command)` syntax,
you can override it by setting `$HGTEST_SHELL` or by passing it to
`run-tests.py --shell <shell>`.
* The (experimental) narrow extension's wire protocol changed. If
you're using it, you'll need to make sure to upgrade server and
client at the same time.
== Internal API Changes ==