annotate mercurial/pure/diffhelpers.py @ 18510:f254ab6207ae stable

subrepo: use sharepath if available when locating the source repo

This is an alternative fix for issue3518, enabling sharing of repositories with
subrepos, without unconditionally setting the default path in the resulting
repo's hgrc file.  Better test coverage is added here, but won't prove this code
is working until fd903f89e42b is backed out.

The problem with the original fix is, if a default path is not available to be
copied over from the share source, the default path on the resulting repo is set
to the source location.  Since that's where the actual repository is stored, the
path is essentially self-referential, so push, pull, incoming and outgoing
effectively operate on itself.  While incoming and outgoing make it look like
nothing was changed, push currently hangs (see issue3657).  In this case where
there is not a real default path, these operations should abort with
"default(-push) not found", like the source repo would.  Note this problem with
the original fix affected repos without subrepos too.

# 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.

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