view mercurial/ancestor.py @ 15708:309e49491253

push: propagate --new-branch and --ssh options when pushing subrepos

Up until now the all the push command options were ignored when pushing
subrepos. In particular, the fact that the --new-branch command was not passed
down to subrepos made it not possible to push a repo when any of its
subrepos had a new branch, even if you used the --new-branch option of the push
command.

In addition the error message was confusing since it showed the following hint:
"--new-branch hint: use 'hg push --new-branch' to create new remote branches".
However using the --new_branch flag did not fix the problem, as it was ignored
when pushing subrepos.

This patch passes the --new-branch and --ssh flags to every subrepo that is
pushed.

Issues/Limitations:

- All subrepo types get these flags, but only the mercurial subrepos use them.
- It is no longer possible to _not_ pass down these flags to subrepos when
pushing:
   * An alternative would be to introduce a --subrepos flag that should be
used to pass down these flags to the subrepos.
   * If we did this, it could make sense to make the --force flag respect this
   new --subrepos flag as well for consistency's sake.
- Matt suggested that the ssh related flags could also be passed down to
subrepos during pull and clone. However it seems that it would be the "update"
command that would need to get those, since subrepos are only pulled on update.
In any case I'd prefer to leave that for a later patch.

# ancestor.py - generic DAG ancestor algorithm for mercurial
#
# Copyright 2006 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

import heapq

def ancestor(a, b, pfunc):
    """
    Returns the common ancestor of a and b that is furthest from a
    root (as measured by longest path) or None if no ancestor is
    found. If there are multiple common ancestors at the same
    distance, the first one found is returned.

    pfunc must return a list of parent vertices for a given vertex
    """

    if a == b:
        return a

    a, b = sorted([a, b])

    # find depth from root of all ancestors
    # depth is stored as a negative for heapq
    parentcache = {}
    visit = [a, b]
    depth = {}
    while visit:
        vertex = visit[-1]
        pl = pfunc(vertex)
        parentcache[vertex] = pl
        if not pl:
            depth[vertex] = 0
            visit.pop()
        else:
            for p in pl:
                if p == a or p == b: # did we find a or b as a parent?
                    return p # we're done
                if p not in depth:
                    visit.append(p)
            if visit[-1] == vertex:
                # -(maximum distance of parents + 1)
                depth[vertex] = min([depth[p] for p in pl]) - 1
                visit.pop()

    # traverse ancestors in order of decreasing distance from root
    def ancestors(vertex):
        h = [(depth[vertex], vertex)]
        seen = set()
        while h:
            d, n = heapq.heappop(h)
            if n not in seen:
                seen.add(n)
                yield (d, n)
                for p in parentcache[n]:
                    heapq.heappush(h, (depth[p], p))

    def generations(vertex):
        sg, s = None, set()
        for g, v in ancestors(vertex):
            if g != sg:
                if sg:
                    yield sg, s
                sg, s = g, set((v,))
            else:
                s.add(v)
        yield sg, s

    x = generations(a)
    y = generations(b)
    gx = x.next()
    gy = y.next()

    # increment each ancestor list until it is closer to root than
    # the other, or they match
    try:
        while True:
            if gx[0] == gy[0]:
                for v in gx[1]:
                    if v in gy[1]:
                        return v
                gy = y.next()
                gx = x.next()
            elif gx[0] > gy[0]:
                gy = y.next()
            else:
                gx = x.next()
    except StopIteration:
        return None