view mercurial/pure/diffhelpers.py @ 21568:8dd17b19e722 stable

subrepo: normalize path in the specific way for problematic encodings

Before this patch, "reporelpath()" uses "rstrip(os.sep)" to trim
"os.sep" at the end of "parent.root" path.

But it doesn't work correctly with some problematic encodings on
Windows, because some multi-byte characters in such encodings contain
'\\' (0x5c) as the tail byte of them.

In such cases, "reporelpath()" leaves unexpected '\\' at the beginning
of the path returned to callers.

"lcalrepository.root" seems not to have tail "os.sep", because it is
always normalized by "os.path.realpath()" in "vfs.__init__()", but in
fact it has tail "os.sep", if it is a root (of the drive): path
normalization trims tail "os.sep" off "/foo/bar/", but doesn't trim
one off "/".

So, just avoiding "rstrip(os.sep)" in "reporelpath()" causes
regression around issue3033 fixed by fccd350acf79.

This patch introduces "pathutil.normasprefix" to normalize specified
path in the specific way for problematic encodings without regression
around issue3033.

# 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