tests/autodiff.py

backout: use commonancestorsheads for checking linear heritage

If two revisions are linearly related, there will only be one ancestor, and
commonancestors and commonancestorsheads would give the same result.
commonancestorsheads is however slightly simpler, faster and more correct.

# Extension dedicated to test patch.diff() upgrade modes
#
#
from mercurial import scmutil, patch, util

def autodiff(ui, repo, *pats, **opts):
    diffopts = patch.diffopts(ui, opts)
    git = opts.get('git', 'no')
    brokenfiles = set()
    losedatafn = None
    if git in ('yes', 'no'):
        diffopts.git = git == 'yes'
        diffopts.upgrade = False
    elif git == 'auto':
        diffopts.git = False
        diffopts.upgrade = True
    elif git == 'warn':
        diffopts.git = False
        diffopts.upgrade = True
        def losedatafn(fn=None, **kwargs):
            brokenfiles.add(fn)
            return True
    elif git == 'abort':
        diffopts.git = False
        diffopts.upgrade = True
        def losedatafn(fn=None, **kwargs):
            raise util.Abort('losing data for %s' % fn)
    else:
        raise util.Abort('--git must be yes, no or auto')

    node1, node2 = scmutil.revpair(repo, [])
    m = scmutil.match(repo[node2], pats, opts)
    it = patch.diff(repo, node1, node2, match=m, opts=diffopts,
                    losedatafn=losedatafn)
    for chunk in it:
        ui.write(chunk)
    for fn in sorted(brokenfiles):
        ui.write(('data lost for: %s\n' % fn))

cmdtable = {
    "autodiff":
        (autodiff,
         [('', 'git', '', 'git upgrade mode (yes/no/auto/warn/abort)'),
          ],
         '[OPTION]... [FILE]...'),
}