hgext/amend.py

amend: error out if the note is greater than 255bytes

In obsmarker we can't store keys and values of more than 255 bytes in metadata.
If we try to do so, ProgrammingError is raised. The note flag to amend stores
the note in obsmetadata. If a user will try to store a larger note, he will
encounter ProgrammingError which is wrong. We must error out early.

Thanks to Yuya for warning about this.

Differential Revision: https://phab.mercurial-scm.org/D1179

# amend.py - provide the amend command
#
# Copyright 2017 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""provide the amend command (EXPERIMENTAL)

This extension provides an ``amend`` command that is similar to
``commit --amend`` but does not prompt an editor.
"""

from __future__ import absolute_import

from mercurial.i18n import _
from mercurial import (
    cmdutil,
    commands,
    error,
    registrar,
)

# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'ships-with-hg-core'

cmdtable = {}
command = registrar.command(cmdtable)

@command('amend',
    [('A', 'addremove', None,
      _('mark new/missing files as added/removed before committing')),
     ('e', 'edit', None, _('invoke editor on commit messages')),
     ('i', 'interactive', None, _('use interactive mode')),
     ('n', 'note', '', _('store a note on the amend')),
    ] + cmdutil.walkopts + cmdutil.commitopts + cmdutil.commitopts2,
    _('[OPTION]... [FILE]...'),
    inferrepo=True)
def amend(ui, repo, *pats, **opts):
    """amend the working copy parent with all or specified outstanding changes

    Similar to :hg:`commit --amend`, but reuse the commit message without
    invoking editor, unless ``--edit`` was set.

    See :hg:`help commit` for more details.
    """
    if len(opts['note']) > 255:
        raise error.Abort(_("cannot store a note of more than 255 bytes"))
    with repo.wlock(), repo.lock():
        if not opts.get('logfile'):
            opts['message'] = opts.get('message') or repo['.'].description()
        opts['amend'] = True
        return commands._docommit(ui, repo, *pats, **opts)