view mercurial/diffutil.py @ 45584:4c8a93ec6908

merge: store commitinfo if these is a dc or cd conflict

delete-changed or changed-delete conflicts can either be resolved by mergetool,
if some tool is passed and using or by user choose something on prompt or user
doing some `hg revert` after choosing the file to remain conflicted.

If the user decides to keep the changed side, on commit we just reuse the parent
filenode. This is mostly fine unless we are in a distributed environment and
people are doing criss-cross merges.

Since, we don't have recursive merges or any other way of describing the end
result of the merge was an explicit choice and it should be differentiated from
it's ancestors, merge algo during criss-cross merges fails to take in account
the explicit choice made by user and end up with a what-can-be-said-wrong-merge.

The solution which we are trying to fix this is by creating a filenode on commit
instead of reusing the parent filenode. This helps differentiate between
pre-merged filenode and post-merge filenode and kind of tells about the choice
user made.

To implement creating new filenode functionality, we store info about these
files in mergestate so that we can read them on commit and force create a new
filenode.

Differential Revision: https://phab.mercurial-scm.org/D8988

# diffutil.py - utility functions related to diff and patch
#
# Copyright 2006 Brendan Cully <[e-mail]>
# Copyright 2007 Chris Mason <[e-mail]>
# Copyright 2018 Octobus <[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.

from __future__ import absolute_import

from .i18n import _

from . import (
    mdiff,
    pycompat,
)


def diffallopts(
    ui, opts=None, untrusted=False, section=b'diff', configprefix=b''
):
    '''return diffopts with all features supported and parsed'''
    return difffeatureopts(
        ui,
        opts=opts,
        untrusted=untrusted,
        section=section,
        git=True,
        whitespace=True,
        formatchanging=True,
        configprefix=configprefix,
    )


def difffeatureopts(
    ui,
    opts=None,
    untrusted=False,
    section=b'diff',
    git=False,
    whitespace=False,
    formatchanging=False,
    configprefix=b'',
):
    '''return diffopts with only opted-in features parsed

    Features:
    - git: git-style diffs
    - whitespace: whitespace options like ignoreblanklines and ignorews
    - formatchanging: options that will likely break or cause correctness issues
      with most diff parsers
    '''

    def get(key, name=None, getter=ui.configbool, forceplain=None):
        if opts:
            v = opts.get(key)
            # diffopts flags are either None-default (which is passed
            # through unchanged, so we can identify unset values), or
            # some other falsey default (eg --unified, which defaults
            # to an empty string). We only want to override the config
            # entries from hgrc with command line values if they
            # appear to have been set, which is any truthy value,
            # True, or False.
            if v or isinstance(v, bool):
                return v
        if forceplain is not None and ui.plain():
            return forceplain
        return getter(
            section, configprefix + (name or key), untrusted=untrusted
        )

    # core options, expected to be understood by every diff parser
    buildopts = {
        b'nodates': get(b'nodates'),
        b'showfunc': get(b'show_function', b'showfunc'),
        b'context': get(b'unified', getter=ui.config),
    }
    buildopts[b'xdiff'] = ui.configbool(b'experimental', b'xdiff')

    if git:
        buildopts[b'git'] = get(b'git')

        # since this is in the experimental section, we need to call
        # ui.configbool directory
        buildopts[b'showsimilarity'] = ui.configbool(
            b'experimental', b'extendedheader.similarity'
        )

        # need to inspect the ui object instead of using get() since we want to
        # test for an int
        hconf = ui.config(b'experimental', b'extendedheader.index')
        if hconf is not None:
            hlen = None
            try:
                # the hash config could be an integer (for length of hash) or a
                # word (e.g. short, full, none)
                hlen = int(hconf)
                if hlen < 0 or hlen > 40:
                    msg = _(b"invalid length for extendedheader.index: '%d'\n")
                    ui.warn(msg % hlen)
            except ValueError:
                # default value
                if hconf == b'short' or hconf == b'':
                    hlen = 12
                elif hconf == b'full':
                    hlen = 40
                elif hconf != b'none':
                    msg = _(b"invalid value for extendedheader.index: '%s'\n")
                    ui.warn(msg % hconf)
            finally:
                buildopts[b'index'] = hlen

    if whitespace:
        buildopts[b'ignorews'] = get(b'ignore_all_space', b'ignorews')
        buildopts[b'ignorewsamount'] = get(
            b'ignore_space_change', b'ignorewsamount'
        )
        buildopts[b'ignoreblanklines'] = get(
            b'ignore_blank_lines', b'ignoreblanklines'
        )
        buildopts[b'ignorewseol'] = get(b'ignore_space_at_eol', b'ignorewseol')
    if formatchanging:
        buildopts[b'text'] = opts and opts.get(b'text')
        binary = None if opts is None else opts.get(b'binary')
        buildopts[b'nobinary'] = (
            not binary
            if binary is not None
            else get(b'nobinary', forceplain=False)
        )
        buildopts[b'noprefix'] = get(b'noprefix', forceplain=False)
        buildopts[b'worddiff'] = get(
            b'word_diff', b'word-diff', forceplain=False
        )

    return mdiff.diffopts(**pycompat.strkwargs(buildopts))