Mercurial > hg
view mercurial/hbisect.py @ 13158:9e7e24052745
merge: fast-forward merge with descendant
issue2538 gives a case where a changeset is merged with its child (which is on
another branch), and to my surprise the result is a real merge with two
parents, not just a "fast forward" "merge" with only the child as parent.
That is essentially the same as issue619.
Is the existing behaviour as intended and correct?
Or is the following fix correct?
Some extra "created new head" pops up with this fix, but it seems to me like
they could be considered correct. The old branch head has been superseeded by
changes on the other branch, and when the changes on the other branch is merged
back to the branch it will introduce a new head not directly related to the
previous branch head.
(I guess the intention with existing behaviour could be to ensure that the
changesets on the branch are directly connected and that no new heads pops up
on merges.)
author | Mads Kiilerich <mads@kiilerich.com> |
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date | Tue, 07 Dec 2010 03:29:21 +0100 |
parents | a4fbbe0fbc38 |
children | e5a59d31bb04 |
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# changelog bisection for mercurial # # Copyright 2007 Matt Mackall # Copyright 2005, 2006 Benoit Boissinot <benoit.boissinot@ens-lyon.org> # # Inspired by git bisect, extension skeleton taken from mq.py. # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. import os from i18n import _ from node import short, hex import util def bisect(changelog, state): """find the next node (if any) for testing during a bisect search. returns a (nodes, number, good) tuple. 'nodes' is the final result of the bisect if 'number' is 0. Otherwise 'number' indicates the remaining possible candidates for the search and 'nodes' contains the next bisect target. 'good' is True if bisect is searching for a first good changeset, False if searching for a first bad one. """ clparents = changelog.parentrevs skip = set([changelog.rev(n) for n in state['skip']]) def buildancestors(bad, good): # only the earliest bad revision matters badrev = min([changelog.rev(n) for n in bad]) goodrevs = [changelog.rev(n) for n in good] goodrev = min(goodrevs) # build visit array ancestors = [None] * (len(changelog) + 1) # an extra for [-1] # set nodes descended from goodrev ancestors[goodrev] = [] for rev in xrange(goodrev + 1, len(changelog)): for prev in clparents(rev): if ancestors[prev] == []: ancestors[rev] = [] # clear good revs from array for node in goodrevs: ancestors[node] = None for rev in xrange(len(changelog), -1, -1): if ancestors[rev] is None: for prev in clparents(rev): ancestors[prev] = None if ancestors[badrev] is None: return badrev, None return badrev, ancestors good = 0 badrev, ancestors = buildancestors(state['bad'], state['good']) if not ancestors: # looking for bad to good transition? good = 1 badrev, ancestors = buildancestors(state['good'], state['bad']) bad = changelog.node(badrev) if not ancestors: # now we're confused if len(state['bad']) == 1 and len(state['good']) == 1: raise util.Abort(_("starting revisions are not directly related")) raise util.Abort(_("inconsistent state, %s:%s is good and bad") % (badrev, short(bad))) # build children dict children = {} visit = [badrev] candidates = [] while visit: rev = visit.pop(0) if ancestors[rev] == []: candidates.append(rev) for prev in clparents(rev): if prev != -1: if prev in children: children[prev].append(rev) else: children[prev] = [rev] visit.append(prev) candidates.sort() # have we narrowed it down to one entry? # or have all other possible candidates besides 'bad' have been skipped? tot = len(candidates) unskipped = [c for c in candidates if (c not in skip) and (c != badrev)] if tot == 1 or not unskipped: return ([changelog.node(rev) for rev in candidates], 0, good) perfect = tot // 2 # find the best node to test best_rev = None best_len = -1 poison = set() for rev in candidates: if rev in poison: # poison children poison.update(children.get(rev, [])) continue a = ancestors[rev] or [rev] ancestors[rev] = None x = len(a) # number of ancestors y = tot - x # number of non-ancestors value = min(x, y) # how good is this test? if value > best_len and rev not in skip: best_len = value best_rev = rev if value == perfect: # found a perfect candidate? quit early break if y < perfect and rev not in skip: # all downhill from here? # poison children poison.update(children.get(rev, [])) continue for c in children.get(rev, []): if ancestors[c]: ancestors[c] = list(set(ancestors[c] + a)) else: ancestors[c] = a + [c] assert best_rev is not None best_node = changelog.node(best_rev) return ([best_node], tot, good) def load_state(repo): state = {'good': [], 'bad': [], 'skip': []} if os.path.exists(repo.join("bisect.state")): for l in repo.opener("bisect.state"): kind, node = l[:-1].split() node = repo.lookup(node) if kind not in state: raise util.Abort(_("unknown bisect kind %s") % kind) state[kind].append(node) return state def save_state(repo, state): f = repo.opener("bisect.state", "w", atomictemp=True) wlock = repo.wlock() try: for kind in state: for node in state[kind]: f.write("%s %s\n" % (kind, hex(node))) f.rename() finally: wlock.release()