discovery: list new remote heads in prepush() on --debug
With this patch applied, Mercurial will list the hashes of new remote heads
if push --debug aborts because of new remote heads (option -f/--force not set).
Example:
$ hg push --debug repo1
using http://example.org/repo1
http auth: user johndoe, password not set
sending between command
pushing to http://example.org/repo1
sending capabilities command
capabilities: changegroupsubset stream=1 lookup pushkey unbundle=HG10GZ,HG10BZ,HG10UN branchmap
sending heads command
searching for changes
common changesets up to
609edbc7853f
sending branchmap command
new remote heads on branch 'default' <- new output line
new remote head
5862c07f53a2 <- new output line
abort: push creates new remote heads on branch 'default'!
(did you forget to merge? use push -f to force)
Compare to without --debug (not changed by this patch, including it here
for reference purposes only):
$ hg push repo1
pushing to http://example.org/repo1
searching for changes
abort: push creates new remote heads on branch 'default'!
(did you forget to merge? use push -f to force)
Motivation for this change:
'hg outgoing' may list a whole lot of benign changesets plus an odd changeset
that will trigger the "new remote heads" abort. It can be hard to spot that
single unwanted changeset (it may be an old forgotten experiment, lingering
in the local repo).
"hg log -r 'heads(outgoing())'" might be useful, but that also lists a head
that may be benign on push.
Inside prepush(), we already know which heads are causing troubles on 'hg push'.
Why not make that info available (at least on --debug)?
This would also be helpful for doing remote support, as the supporter can ask
the user to paste the output of 'hg push --debug' on error and then ask further
questions about the heads listed.
# discovery.py - protocol changeset discovery functions
#
# Copyright 2010 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from node import nullid, short
from i18n import _
import util, error
def findcommonincoming(repo, remote, heads=None, force=False):
"""Return a tuple (common, missing roots, heads) used to identify
missing nodes from remote.
If a list of heads is specified, return only nodes which are heads
or ancestors of these heads.
"""
m = repo.changelog.nodemap
search = []
fetch = set()
seen = set()
seenbranch = set()
base = set()
if not heads:
heads = remote.heads()
if repo.changelog.tip() == nullid:
base.add(nullid)
if heads != [nullid]:
return [nullid], [nullid], list(heads)
return [nullid], [], []
# assume we're closer to the tip than the root
# and start by examining the heads
repo.ui.status(_("searching for changes\n"))
unknown = []
for h in heads:
if h not in m:
unknown.append(h)
else:
base.add(h)
heads = unknown
if not unknown:
return list(base), [], []
req = set(unknown)
reqcnt = 0
# search through remote branches
# a 'branch' here is a linear segment of history, with four parts:
# head, root, first parent, second parent
# (a branch always has two parents (or none) by definition)
unknown = remote.branches(unknown)
while unknown:
r = []
while unknown:
n = unknown.pop(0)
if n[0] in seen:
continue
repo.ui.debug("examining %s:%s\n"
% (short(n[0]), short(n[1])))
if n[0] == nullid: # found the end of the branch
pass
elif n in seenbranch:
repo.ui.debug("branch already found\n")
continue
elif n[1] and n[1] in m: # do we know the base?
repo.ui.debug("found incomplete branch %s:%s\n"
% (short(n[0]), short(n[1])))
search.append(n[0:2]) # schedule branch range for scanning
seenbranch.add(n)
else:
if n[1] not in seen and n[1] not in fetch:
if n[2] in m and n[3] in m:
repo.ui.debug("found new changeset %s\n" %
short(n[1]))
fetch.add(n[1]) # earliest unknown
for p in n[2:4]:
if p in m:
base.add(p) # latest known
for p in n[2:4]:
if p not in req and p not in m:
r.append(p)
req.add(p)
seen.add(n[0])
if r:
reqcnt += 1
repo.ui.progress(_('searching'), reqcnt, unit=_('queries'))
repo.ui.debug("request %d: %s\n" %
(reqcnt, " ".join(map(short, r))))
for p in xrange(0, len(r), 10):
for b in remote.branches(r[p:p + 10]):
repo.ui.debug("received %s:%s\n" %
(short(b[0]), short(b[1])))
unknown.append(b)
# do binary search on the branches we found
while search:
newsearch = []
reqcnt += 1
repo.ui.progress(_('searching'), reqcnt, unit=_('queries'))
for n, l in zip(search, remote.between(search)):
l.append(n[1])
p = n[0]
f = 1
for i in l:
repo.ui.debug("narrowing %d:%d %s\n" % (f, len(l), short(i)))
if i in m:
if f <= 2:
repo.ui.debug("found new branch changeset %s\n" %
short(p))
fetch.add(p)
base.add(i)
else:
repo.ui.debug("narrowed branch search to %s:%s\n"
% (short(p), short(i)))
newsearch.append((p, i))
break
p, f = i, f * 2
search = newsearch
# sanity check our fetch list
for f in fetch:
if f in m:
raise error.RepoError(_("already have changeset ")
+ short(f[:4]))
base = list(base)
if base == [nullid]:
if force:
repo.ui.warn(_("warning: repository is unrelated\n"))
else:
raise util.Abort(_("repository is unrelated"))
repo.ui.debug("found new changesets starting at " +
" ".join([short(f) for f in fetch]) + "\n")
repo.ui.progress(_('searching'), None)
repo.ui.debug("%d total queries\n" % reqcnt)
return base, list(fetch), heads
def findoutgoing(repo, remote, base=None, remoteheads=None, force=False):
"""Return list of nodes that are roots of subsets not in remote
If base dict is specified, assume that these nodes and their parents
exist on the remote side.
If remotehead is specified, assume it is the list of the heads from
the remote repository.
"""
if base is None:
base = findcommonincoming(repo, remote, heads=remoteheads,
force=force)[0]
else:
base = list(base)
repo.ui.debug("common changesets up to "
+ " ".join(map(short, base)) + "\n")
remain = set(repo.changelog.nodemap)
# prune everything remote has from the tree
remain.remove(nullid)
remove = base
while remove:
n = remove.pop(0)
if n in remain:
remain.remove(n)
for p in repo.changelog.parents(n):
remove.append(p)
# find every node whose parents have been pruned
subset = []
# find every remote head that will get new children
for n in remain:
p1, p2 = repo.changelog.parents(n)
if p1 not in remain and p2 not in remain:
subset.append(n)
return subset
def prepush(repo, remote, force, revs, newbranch):
'''Analyze the local and remote repositories and determine which
changesets need to be pushed to the remote. Return value depends
on circumstances:
If we are not going to push anything, return a tuple (None,
outgoing) where outgoing is 0 if there are no outgoing
changesets and 1 if there are, but we refuse to push them
(e.g. would create new remote heads).
Otherwise, return a tuple (changegroup, remoteheads), where
changegroup is a readable file-like object whose read() returns
successive changegroup chunks ready to be sent over the wire and
remoteheads is the list of remote heads.'''
remoteheads = remote.heads()
common, inc, rheads = findcommonincoming(repo, remote, heads=remoteheads,
force=force)
cl = repo.changelog
update = findoutgoing(repo, remote, common, remoteheads)
outg, bases, heads = cl.nodesbetween(update, revs)
if not bases:
repo.ui.status(_("no changes found\n"))
return None, 1
if not force and remoteheads != [nullid]:
if remote.capable('branchmap'):
# Check for each named branch if we're creating new remote heads.
# To be a remote head after push, node must be either:
# - unknown locally
# - a local outgoing head descended from update
# - a remote head that's known locally and not
# ancestral to an outgoing head
# 1. Create set of branches involved in the push.
branches = set(repo[n].branch() for n in outg)
# 2. Check for new branches on the remote.
remotemap = remote.branchmap()
newbranches = branches - set(remotemap)
if newbranches and not newbranch: # new branch requires --new-branch
branchnames = ', '.join(sorted(newbranches))
raise util.Abort(_("push creates new remote branches: %s!")
% branchnames,
hint=_("use 'hg push --new-branch' to create"
" new remote branches"))
branches.difference_update(newbranches)
# 3. Construct the initial oldmap and newmap dicts.
# They contain information about the remote heads before and
# after the push, respectively.
# Heads not found locally are not included in either dict,
# since they won't be affected by the push.
# unsynced contains all branches with incoming changesets.
oldmap = {}
newmap = {}
unsynced = set()
for branch in branches:
remotebrheads = remotemap[branch]
prunedbrheads = [h for h in remotebrheads if h in cl.nodemap]
oldmap[branch] = prunedbrheads
newmap[branch] = list(prunedbrheads)
if len(remotebrheads) > len(prunedbrheads):
unsynced.add(branch)
# 4. Update newmap with outgoing changes.
# This will possibly add new heads and remove existing ones.
ctxgen = (repo[n] for n in outg)
repo._updatebranchcache(newmap, ctxgen)
else:
# 1-4b. old servers: Check for new topological heads.
# Construct {old,new}map with branch = None (topological branch).
# (code based on _updatebranchcache)
oldheads = set(h for h in remoteheads if h in cl.nodemap)
newheads = oldheads.union(outg)
if len(newheads) > 1:
for latest in reversed(outg):
if latest not in newheads:
continue
minhrev = min(cl.rev(h) for h in newheads)
reachable = cl.reachable(latest, cl.node(minhrev))
reachable.remove(latest)
newheads.difference_update(reachable)
branches = set([None])
newmap = {None: newheads}
oldmap = {None: oldheads}
unsynced = inc and branches or set()
# 5. Check for new heads.
# If there are more heads after the push than before, a suitable
# error message, depending on unsynced status, is displayed.
error = None
for branch in branches:
newhs = set(newmap[branch])
oldhs = set(oldmap[branch])
if len(newhs) > len(oldhs):
if error is None:
if branch:
error = _("push creates new remote heads "
"on branch '%s'!") % branch
else:
error = _("push creates new remote heads!")
if branch in unsynced:
hint = _("you should pull and merge or "
"use push -f to force")
else:
hint = _("did you forget to merge? "
"use push -f to force")
if branch:
repo.ui.debug("new remote heads on branch '%s'\n" % branch)
for h in (newhs - oldhs):
repo.ui.debug("new remote head %s\n" % short(h))
if error:
raise util.Abort(error, hint=hint)
# 6. Check for unsynced changes on involved branches.
if unsynced:
repo.ui.warn(_("note: unsynced remote changes!\n"))
if revs is None:
# use the fast path, no race possible on push
nodes = repo.changelog.findmissing(common)
cg = repo._changegroup(nodes, 'push')
else:
cg = repo.changegroupsubset(update, revs, 'push')
return cg, remoteheads