view mercurial/pure/diffhelpers.py @ 33048:46fa46608ca5

namespaces: record and expose whether namespace is built-in

Currently, the templating layer tends to treat each namespace
as a one-off, with explicit usage of {bookmarks}, {tags}, {branch},
etc instead of using {namespaces}. It would be really useful if
we could iterate over namespaces and operate on them generically.
However, some consumers may wish to differentiate namespaces by
whether they are built-in to core Mercurial or provided by extensions.
Expected use cases include ignoring non-built-in namespaces or
emitting a generic label for non-built-in namespaces.

This commit introduces an attribute on namespace instances
that says whether the namespace is "built-in" and then exposes
this to the templating layer.

As part of this, we implement a reusable extension for defining
custom names on each changeset for testing. A second consumer
will be introduced in a subsequent commit.

# 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