view hgext/hooklib/reject_merge_commits.py @ 51756:a53162bd73ed

subrepo: drop the default value of None for the archive matcher

This was flagged by pytype after adding hints to `match.subdirmatcher` that it
takes a non-optional matcher.  That matcher argument is used without a guard in
the subdirmatcher constructor, so that's the correct restriction.

I don't think this fixes a bug in practice because the only way these are
invoked is either by a parent `hgsubrepo.archive()`, `archival.archive()`, or
the largefiles override of these.  The `hgsubrepo.archive()` case (and the
largefiles override) uses what the caller provided, so the caller will
eventually be `archival.archive()` (or the largfiles override) up the call
chain.  The `archival.archive()` method also has None for its matcher's default
arg.  However, the three callers of that (`commands.archive()`,
`webcommands.archive()`, and `extdiff.snapshot()`) all provide a matcher
argument, so the None case can never occur unless a 3rd party extension swaps it
for None.  Sadly, we can't make the argument on the `archival.archive()`
non-optional because there is a kwarg prior to it.

Even though the largefiles override of `archival.archive()` is provided a valid
matcher, we duplicate the internal creation of the matcher that the original
`archival.archive()` does for consistency.  By eliminating an impossible to hit
case, we can simplify some of the subrepo code too, by dropping unreachable
code.

# Copyright 2020 Joerg Sonnenberger <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

"""reject_merge_commits is a hook to check new changesets for merge commits.
Merge commits are allowed only between different branches, i.e. merging
a feature branch into the main development branch. This can be used to
enforce policies for linear commit histories.

Usage:
  [hooks]
  pretxnchangegroup.reject_merge_commits = \
    python:hgext.hooklib.reject_merge_commits.hook
"""


from mercurial.i18n import _
from mercurial import (
    error,
    pycompat,
)


def hook(ui, repo, hooktype, node=None, **kwargs):
    if hooktype != b"pretxnchangegroup":
        raise error.Abort(
            _(b'Unsupported hook type %r') % pycompat.bytestr(hooktype)
        )

    ctx = repo.unfiltered()[node]
    for rev in repo.changelog.revs(start=ctx.rev()):
        rev = repo[rev]
        parents = rev.parents()
        if len(parents) < 2:
            continue
        if all(repo[p].branch() == rev.branch() for p in parents):
            raise error.Abort(
                _(
                    b'%s rejected as merge on the same branch. '
                    b'Please consider rebase.'
                )
                % rev
            )