convert: add a mode where mercurial_sink skips empty revisions. The getchanges function of some converter_source classes can return some false positives. I.e. they sometimes claim that a file "foo" was changed in some revision, even though its contents are still the same. convert_svn is particularly bad, but I think this can also happen with convert_cvs and, at least in theory, with mercurial_source. For regular conversions this is not really a problem - as long as getfile returns the right contents, we'll get a converted revision with the right contents. But when we use --filemap, this could lead to superfluous revisions being converted. Instead of fixing every converter_source, I decided to change mercurial_sink to work around this problem. When --filemap is used, we're interested only in revisions that touch some specific files. If a revision doesn't change any of these files, then we're not interested in it (at least for revisions with a single parent; merges are special). For mercurial_sink, we abuse this property and rollback a commit if the manifest text hasn't changed. This avoids duplicating the logic from localrepo.filecommit to detect unchanged files.

#!/usr/bin/env python

import os
from mercurial import ui

hgrc = os.environ['HGRCPATH']

print '      hgrc settings    command line options      final result   '
print '    quiet verbo debug   quiet verbo debug      quiet verbo debug'

for i in xrange(64):
    hgrc_quiet   = bool(i & 1<<0)
    hgrc_verbose = bool(i & 1<<1)
    hgrc_debug   = bool(i & 1<<2)
    cmd_quiet    = bool(i & 1<<3)
    cmd_verbose  = bool(i & 1<<4)
    cmd_debug    = bool(i & 1<<5)

    f = open(hgrc, 'w')
    f.write('[ui]\n')
    if hgrc_quiet:
        f.write('quiet = True\n')
    if hgrc_verbose:
        f.write('verbose = True\n')
    if hgrc_debug:
        f.write('debug = True\n')
    f.close()

    u = ui.ui()
    u.updateopts(quiet=cmd_quiet, verbose=cmd_verbose, debug=cmd_debug)

    check = ''
    if u.debugflag:
        if not u.verbose or u.quiet:
            check = ' *'
    elif u.verbose and u.quiet:
        check = ' +'

    print ('%2d  %5s %5s %5s   %5s %5s %5s  ->  %5s %5s %5s%s'
           % (i, hgrc_quiet, hgrc_verbose, hgrc_debug,
              cmd_quiet, cmd_verbose, cmd_debug,
              u.quiet, u.verbose, u.debugflag, check))