mercurial/diffhelper.py
author Valentin Gatien-Baron <valentin.gatienbaron@gmail.com>
Tue, 25 Feb 2020 20:27:39 -0500
changeset 44439 edc8504bc26b
parent 43077 687b865b95ad
child 45154 10f48720ef95
permissions -rw-r--r--
exchange: turn on option that makes concurrent pushes work better The motivation is simply to make hg work better out of the box. This is a slight backwards compatibility break, because client extensions could have assumed that the list of heads the client sees during discovery will be the list of heads during the entirety of the push. It seems unlikely to matter, and not worth mentioning. There's a fair amount of diff in tests, but this is just due to sending a few more bytes on the wire, except for test-acl.t. The extra "invalid branch cache" lines in test-acl.t don't seem to indicate a problem: the branchcache now get computed during the bundle application (because of the check:updated-heads bundle part), but doesn't get rolled back when transactions rollback, thus causing a message in the next operation computing the branch cache. Before this change, I assume the branchcache was only computed on transaction commit, so not computed at all when the transactions roll back, thus no messages. Differential Revision: https://phab.mercurial-scm.org/D8202

# diffhelper.py - helper routines for patch
#
# Copyright 2009 Matt Mackall <mpm@selenic.com> and others
#
# 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 (
    error,
    pycompat,
)


def addlines(fp, hunk, lena, lenb, a, b):
    """Read lines from fp into the hunk

    The hunk is parsed into two arrays, a and b. a gets the old state of
    the text, b gets the new state. The control char from the hunk is saved
    when inserting into a, but not b (for performance while deleting files.)
    """
    while True:
        todoa = lena - len(a)
        todob = lenb - len(b)
        num = max(todoa, todob)
        if num == 0:
            break
        for i in pycompat.xrange(num):
            s = fp.readline()
            if not s:
                raise error.ParseError(_(b'incomplete hunk'))
            if s == b"\\ No newline at end of file\n":
                fixnewline(hunk, a, b)
                continue
            if s == b'\n' or s == b'\r\n':
                # Some patches may be missing the control char
                # on empty lines. Supply a leading space.
                s = b' ' + s
            hunk.append(s)
            if s.startswith(b'+'):
                b.append(s[1:])
            elif s.startswith(b'-'):
                a.append(s)
            else:
                b.append(s[1:])
                a.append(s)


def fixnewline(hunk, a, b):
    """Fix up the last lines of a and b when the patch has no newline at EOF"""
    l = hunk[-1]
    # tolerate CRLF in last line
    if l.endswith(b'\r\n'):
        hline = l[:-2]
    else:
        hline = l[:-1]

    if hline.startswith((b' ', b'+')):
        b[-1] = hline[1:]
    if hline.startswith((b' ', b'-')):
        a[-1] = hline
    hunk[-1] = hline


def testhunk(a, b, bstart):
    """Compare the lines in a with the lines in b

    a is assumed to have a control char at the start of each line, this char
    is ignored in the compare.
    """
    alen = len(a)
    blen = len(b)
    if alen > blen - bstart or bstart < 0:
        return False
    for i in pycompat.xrange(alen):
        if a[i][1:] != b[i + bstart]:
            return False
    return True