mercurial/ignore.py

convert: fix mercurial_sink.putcommit

Changeset 4ebc8693ce72 added some code to putcommit to avoid creating a
revision that touches no files, but this can break regular conversions
from some repositories:

- conceptually, since we're converting a repo, we should try to make
  the new hg repo as similar as possible to the original repo - we
  should create a new changeset, even if the original revision didn't
  touch any files (maybe the commit message had some important bit);

- even if a "regular" revision that doesn't touch any file may seem
  weird (and maybe even broken), it's completely legitimate for a merge
  revision to not touch any file, and, if we just skip it, the
  converted repo will end up with wrong history and possibly an extra
  head.

  As an example, say the crew and main hg repos are sync'ed.  Somebody
  sends an important patch to the mailing list.  Matt quickly applies
  and pushes it.  But at the same time somebody also applies it to crew
  and pushes it.  Suppose the commit message ended up being a bit
  different (say, there was a typo and somebody didn't fix it) or that
  the date ended up being different (because of different patch-applying
  scripts): the changeset hashes will be different, but the manifests
  will be the same.

  Since both changesets were pushed to public repos, it's hard to recall
  them.  If both are merged, the manifest from the resulting merge
  revision will have the exact same contents as its parents - i.e. the
  merge revision really doesn't touch any file at all.

To keep the file filtering stuff "working", the generic code was changed
to skip empty revisions if we're filtering the repo, fixing a bug in the
process (we want parents[0] instead of tip).

# ignore.py - ignored file handling for mercurial
#
# Copyright 2007 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.

from i18n import _
import util

def _parselines(fp):
    for line in fp:
        if not line.endswith('\n'):
            line += '\n'
        escape = False
        for i in xrange(len(line)):
            if escape: escape = False
            elif line[i] == '\\': escape = True
            elif line[i] == '#': break
        line = line[:i].rstrip()
        if line:
            yield line

def ignore(root, files, warn):
    '''return the contents of .hgignore files as a list of patterns.

    the files parsed for patterns include:
    .hgignore in the repository root
    any additional files specified in the [ui] section of ~/.hgrc

    trailing white space is dropped.
    the escape character is backslash.
    comments start with #.
    empty lines are skipped.

    lines can be of the following formats:

    syntax: regexp # defaults following lines to non-rooted regexps
    syntax: glob   # defaults following lines to non-rooted globs
    re:pattern     # non-rooted regular expression
    glob:pattern   # non-rooted glob
    pattern        # pattern of the current default type'''

    syntaxes = {'re': 'relre:', 'regexp': 'relre:', 'glob': 'relglob:'}
    pats = {}
    for f in files:
        try:
            pats[f] = []
            fp = open(f)
            syntax = 'relre:'
            for line in _parselines(fp):
                if line.startswith('syntax:'):
                    s = line[7:].strip()
                    try:
                        syntax = syntaxes[s]
                    except KeyError:
                        warn(_("%s: ignoring invalid syntax '%s'\n") % (f, s))
                    continue
                pat = syntax + line
                for s, rels in syntaxes.items():
                    if line.startswith(rels):
                        pat = line
                        break
                    elif line.startswith(s+':'):
                        pat = rels + line[len(s)+1:]
                        break
                pats[f].append(pat)
        except IOError, inst:
            if f != files[0]:
                warn(_("skipping unreadable ignore file '%s': %s\n") %
                     (f, inst.strerror))

    allpats = []
    [allpats.extend(patlist) for patlist in pats.values()]
    if not allpats:
        return util.never

    try:
        files, ignorefunc, anypats = (
            util.matcher(root, inc=allpats, src='.hgignore'))
    except util.Abort:
        # Re-raise an exception where the src is the right file
        for f, patlist in pats.items():
            files, ignorefunc, anypats = (
                util.matcher(root, inc=patlist, src=f))

    return ignorefunc


    '''default match function used by dirstate and
    localrepository.  this honours the repository .hgignore file
    and any other files specified in the [ui] section of .hgrc.'''