view tests/hghave @ 17103:5146de7bce96

convert: keep branch switching merges with ancestors (issue3340)

When running convert with a filemap, merge parents which are ancestors
of other parents are ignored. This is hardly a problem when parents
belong to the same branch, but the result could be confusing when named
branches are involved. With:

  -o-a1-a2-a3...     <- A
    \           \
     b1-b2-b3...-m-  <- B

If all b* revisions are discarded, it is useful to preserve 'm' even if
it is empty after filtering to record the branch switch.

This patch makes filemap preserve "ancestor parents" if there is no
"non-ancestor parent" on the same branch than the merge revision.

Remarks:
- I am not completely convinced by the reasons given above and those
  detailed by Matt in this thread:

http://selenic.com/pipermail/mercurial-devel/2012-May/040627.html

  The properties we try to preserve are not clearly defined. That said,
  I know this patch already helped someone on IRC and the tests output
  look reasonable.

- This is a new version of the original "convert: filemap must preserve
  fast-forward merges" patch. It has exactly the same output for 2
  parents merges, the additional complexity is here to handle more than
  two parents.

#!/usr/bin/env python
"""Test the running system for features availability. Exit with zero
if all features are there, non-zero otherwise. If a feature name is
prefixed with "no-", the absence of feature is tested.
"""
import optparse
import sys
import hghave

checks = hghave.checks

def list_features():
    for name, feature in checks.iteritems():
        desc = feature[1]
        print name + ':', desc

def test_features():
    failed = 0
    for name, feature in checks.iteritems():
        check, _ = feature
        try:
            check()
        except Exception, e:
            print "feature %s failed:  %s" % (name, e)
            failed += 1
    return failed

parser = optparse.OptionParser("%prog [options] [features]")
parser.add_option("--test-features", action="store_true",
                  help="test available features")
parser.add_option("--list-features", action="store_true",
                  help="list available features")
parser.add_option("-q", "--quiet", action="store_true",
                  help="check features silently")

if __name__ == '__main__':
    options, args = parser.parse_args()
    if options.list_features:
        list_features()
        sys.exit(0)

    if options.test_features:
        sys.exit(test_features())

    quiet = options.quiet

    failures = 0

    def error(msg):
        global failures
        if not quiet:
            sys.stderr.write(msg + '\n')
        failures += 1

    for feature in args:
        negate = feature.startswith('no-')
        if negate:
            feature = feature[3:]

        if feature not in checks:
            error('skipped: unknown feature: ' + feature)
            continue

        check, desc = checks[feature]
        try:
            available = check()
        except Exception, e:
            error('hghave check failed: ' + feature)
            continue

        if not negate and not available:
            error('skipped: missing feature: ' + desc)
        elif negate and available:
            error('skipped: system supports %s' % desc)

    if failures != 0:
        sys.exit(1)