view mercurial/pure/diffhelpers.py @ 28102:bd74b5e0d2c0

destutil: extract all 'mergedest' abort messages into a dictionary

We plan to be able to reuse this function for rebase. The error
message explicitly refers to "merge" in multiple places. So we'll need
to be able to use different messages. The first step of that is to
extract all messages in a dedicated dictionary and use them
indirectly.

As a side effect it clarifies the actual function and opens the way to
various cleanups and fixes in future changesets.

# diffhelpers.py - pure Python implementation of diffhelpers.c
#
# Copyright 2009 Matt Mackall <[e-mail]> 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

def addlines(fp, hunk, lena, lenb, a, b):
    while True:
        todoa = lena - len(a)
        todob = lenb - len(b)
        num = max(todoa, todob)
        if num == 0:
            break
        for i in xrange(num):
            s = fp.readline()
            c = s[0]
            if s == "\\ No newline at end of file\n":
                fix_newline(hunk, a, b)
                continue
            if c == "\n":
                # Some patches may be missing the control char
                # on empty lines. Supply a leading space.
                s = " \n"
            hunk.append(s)
            if c == "+":
                b.append(s[1:])
            elif c == "-":
                a.append(s)
            else:
                b.append(s[1:])
                a.append(s)
    return 0

def fix_newline(hunk, a, b):
    l = hunk[-1]
    # tolerate CRLF in last line
    if l.endswith('\r\n'):
        hline = l[:-2]
    else:
        hline = l[:-1]
    c = hline[0]

    if c in " +":
        b[-1] = hline[1:]
    if c in " -":
        a[-1] = hline
    hunk[-1] = hline
    return 0


def testhunk(a, b, bstart):
    alen = len(a)
    blen = len(b)
    if alen > blen - bstart:
        return -1
    for i in xrange(alen):
        if a[i][1:] != b[i + bstart]:
            return -1
    return 0