annotate mercurial/revset.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.)

# revset.py - revision set queries for mercurial
#
# Copyright 2010 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 re
import parser, util, error, discovery
import match as matchmod
from i18n import _, gettext

elements = {
    "(": (20, ("group", 1, ")"), ("func", 1, ")")),
    "-": (5, ("negate", 19), ("minus", 5)),
    "::": (17, ("dagrangepre", 17), ("dagrange", 17),
           ("dagrangepost", 17)),
    "..": (17, ("dagrangepre", 17), ("dagrange", 17),
           ("dagrangepost", 17)),
    ":": (15, ("rangepre", 15), ("range", 15), ("rangepost", 15)),
    "not": (10, ("not", 10)),
    "!": (10, ("not", 10)),
    "and": (5, None, ("and", 5)),
    "&": (5, None, ("and", 5)),
    "or": (4, None, ("or", 4)),
    "|": (4, None, ("or", 4)),
    "+": (4, None, ("or", 4)),
    ",": (2, None, ("list", 2)),
    ")": (0, None, None),
    "symbol": (0, ("symbol",), None),
    "string": (0, ("string",), None),
    "end": (0, None, None),
}

keywords = set(['and', 'or', 'not'])

def tokenize(program):
    pos, l = 0, len(program)
    while pos < l:
        c = program[pos]
        if c.isspace(): # skip inter-token whitespace
            pass
        elif c == ':' and program[pos:pos + 2] == '::': # look ahead carefully
            yield ('::', None, pos)
            pos += 1 # skip ahead
        elif c == '.' and program[pos:pos + 2] == '..': # look ahead carefully
            yield ('..', None, pos)
            pos += 1 # skip ahead
        elif c in "():,-|&+!": # handle simple operators
            yield (c, None, pos)
        elif (c in '"\'' or c == 'r' and
              program[pos:pos + 2] in ("r'", 'r"')): # handle quoted strings
            if c == 'r':
                pos += 1
                c = program[pos]
                decode = lambda x: x
            else:
                decode = lambda x: x.decode('string-escape')
            pos += 1
            s = pos
            while pos < l: # find closing quote
                d = program[pos]
                if d == '\\': # skip over escaped characters
                    pos += 2
                    continue
                if d == c:
                    yield ('string', decode(program[s:pos]), s)
                    break
                pos += 1
            else:
                raise error.ParseError(_("unterminated string"), s)
        elif c.isalnum() or c in '._' or ord(c) > 127: # gather up a symbol/keyword
            s = pos
            pos += 1
            while pos < l: # find end of symbol
                d = program[pos]
                if not (d.isalnum() or d in "._" or ord(d) > 127):
                    break
                if d == '.' and program[pos - 1] == '.': # special case for ..
                    pos -= 1
                    break
                pos += 1
            sym = program[s:pos]
            if sym in keywords: # operator keywords
                yield (sym, None, s)
            else:
                yield ('symbol', sym, s)
            pos -= 1
        else:
            raise error.ParseError(_("syntax error"), pos)
        pos += 1
    yield ('end', None, pos)

# helpers

def getstring(x, err):
    if x and (x[0] == 'string' or x[0] == 'symbol'):
        return x[1]
    raise error.ParseError(err)

def getlist(x):
    if not x:
        return []
    if x[0] == 'list':
        return getlist(x[1]) + [x[2]]
    return [x]

def getargs(x, min, max, err):
    l = getlist(x)
    if len(l) < min or len(l) > max:
        raise error.ParseError(err)
    return l

def getset(repo, subset, x):
    if not x:
        raise error.ParseError(_("missing argument"))
    return methods[x[0]](repo, subset, *x[1:])

# operator methods

def stringset(repo, subset, x):
    x = repo[x].rev()
    if x == -1 and len(subset) == len(repo):
        return [-1]
    if x in subset:
        return [x]
    return []

def symbolset(repo, subset, x):
    if x in symbols:
        raise error.ParseError(_("can't use %s here") % x)
    return stringset(repo, subset, x)

def rangeset(repo, subset, x, y):
    m = getset(repo, subset, x)
    if not m:
        m = getset(repo, range(len(repo)), x)

    n = getset(repo, subset, y)
    if not n:
        n = getset(repo, range(len(repo)), y)

    if not m or not n:
        return []
    m, n = m[0], n[-1]

    if m < n:
        r = range(m, n + 1)
    else:
        r = range(m, n - 1, -1)
    s = set(subset)
    return [x for x in r if x in s]

def andset(repo, subset, x, y):
    return getset(repo, getset(repo, subset, x), y)

def orset(repo, subset, x, y):
    s = set(getset(repo, subset, x))
    s |= set(getset(repo, [r for r in subset if r not in s], y))
    return [r for r in subset if r in s]

def notset(repo, subset, x):
    s = set(getset(repo, subset, x))
    return [r for r in subset if r not in s]

def listset(repo, subset, a, b):
    raise error.ParseError(_("can't use a list in this context"))

def func(repo, subset, a, b):
    if a[0] == 'symbol' and a[1] in symbols:
        return symbols[a[1]](repo, subset, b)
    raise error.ParseError(_("not a function: %s") % a[1])

# functions

def node(repo, subset, x):
    """``id(string)``
    Revision non-ambiguously specified by the given hex string prefix.
    """
    # i18n: "id" is a keyword
    l = getargs(x, 1, 1, _("id requires one argument"))
    # i18n: "id" is a keyword
    n = getstring(l[0], _("id requires a string"))
    if len(n) == 40:
        rn = repo[n].rev()
    else:
        rn = repo.changelog.rev(repo.changelog._partialmatch(n))
    return [r for r in subset if r == rn]

def rev(repo, subset, x):
    """``rev(number)``
    Revision with the given numeric identifier.
    """
    # i18n: "rev" is a keyword
    l = getargs(x, 1, 1, _("rev requires one argument"))
    try:
        # i18n: "rev" is a keyword
        l = int(getstring(l[0], _("rev requires a number")))
    except ValueError:
        # i18n: "rev" is a keyword
        raise error.ParseError(_("rev expects a number"))
    return [r for r in subset if r == l]

def p1(repo, subset, x):
    """``p1([set])``
    First parent of changesets in set, or the working directory.
    """
    if x is None:
        p = repo[x].parents()[0].rev()
        return [r for r in subset if r == p]

    ps = set()
    cl = repo.changelog
    for r in getset(repo, range(len(repo)), x):
        ps.add(cl.parentrevs(r)[0])
    return [r for r in subset if r in ps]

def p2(repo, subset, x):
    """``p2([set])``
    Second parent of changesets in set, or the working directory.
    """
    if x is None:
        ps = repo[x].parents()
        try:
            p = ps[1].rev()
            return [r for r in subset if r == p]
        except IndexError:
            return []

    ps = set()
    cl = repo.changelog
    for r in getset(repo, range(len(repo)), x):
        ps.add(cl.parentrevs(r)[1])
    return [r for r in subset if r in ps]

def parents(repo, subset, x):
    """``parents([set])``
    The set of all parents for all changesets in set, or the working directory.
    """
    if x is None:
        ps = tuple(p.rev() for p in repo[x].parents())
        return [r for r in subset if r in ps]

    ps = set()
    cl = repo.changelog
    for r in getset(repo, range(len(repo)), x):
        ps.update(cl.parentrevs(r))
    return [r for r in subset if r in ps]

def maxrev(repo, subset, x):
    """``max(set)``
    Changeset with highest revision number in set.
    """
    s = getset(repo, subset, x)
    if s:
        m = max(s)
        if m in subset:
            return [m]
    return []

def minrev(repo, subset, x):
    """``min(set)``
    Changeset with lowest revision number in set.
    """
    s = getset(repo, subset, x)
    if s:
        m = min(s)
        if m in subset:
            return [m]
    return []

def limit(repo, subset, x):
    """``limit(set, n)``
    First n members of set.
    """
    # i18n: "limit" is a keyword
    l = getargs(x, 2, 2, _("limit requires two arguments"))
    try:
        # i18n: "limit" is a keyword
        lim = int(getstring(l[1], _("limit requires a number")))
    except ValueError:
        # i18n: "limit" is a keyword
        raise error.ParseError(_("limit expects a number"))
    return getset(repo, subset, l[0])[:lim]

def children(repo, subset, x):
    """``children(set)``
    Child changesets of changesets in set.
    """
    cs = set()
    cl = repo.changelog
    s = set(getset(repo, range(len(repo)), x))
    for r in xrange(0, len(repo)):
        for p in cl.parentrevs(r):
            if p in s:
                cs.add(r)
    return [r for r in subset if r in cs]

def branch(repo, subset, x):
    """``branch(set)``
    All changesets belonging to the branches of changesets in set.
    """
    s = getset(repo, range(len(repo)), x)
    b = set()
    for r in s:
        b.add(repo[r].branch())
    s = set(s)
    return [r for r in subset if r in s or repo[r].branch() in b]

def ancestor(repo, subset, x):
    """``ancestor(single, single)``
    Greatest common ancestor of the two changesets.
    """
    # i18n: "ancestor" is a keyword
    l = getargs(x, 2, 2, _("ancestor requires two arguments"))
    r = range(len(repo))
    a = getset(repo, r, l[0])
    b = getset(repo, r, l[1])
    if len(a) != 1 or len(b) != 1:
        # i18n: "ancestor" is a keyword
        raise error.ParseError(_("ancestor arguments must be single revisions"))
    an = [repo[a[0]].ancestor(repo[b[0]]).rev()]

    return [r for r in an if r in subset]

def ancestors(repo, subset, x):
    """``ancestors(set)``
    Changesets that are ancestors of a changeset in set.
    """
    args = getset(repo, range(len(repo)), x)
    if not args:
        return []
    s = set(repo.changelog.ancestors(*args)) | set(args)
    return [r for r in subset if r in s]

def descendants(repo, subset, x):
    """``descendants(set)``
    Changesets which are descendants of changesets in set.
    """
    args = getset(repo, range(len(repo)), x)
    if not args:
        return []
    s = set(repo.changelog.descendants(*args)) | set(args)
    return [r for r in subset if r in s]

def follow(repo, subset, x):
    """``follow()``
    An alias for ``::.`` (ancestors of the working copy's first parent).
    """
    # i18n: "follow" is a keyword
    getargs(x, 0, 0, _("follow takes no arguments"))
    p = repo['.'].rev()
    s = set(repo.changelog.ancestors(p)) | set([p])
    return [r for r in subset if r in s]

def date(repo, subset, x):
    """``date(interval)``
    Changesets within the interval, see :hg:`help dates`.
    """
    # i18n: "date" is a keyword
    ds = getstring(x, _("date requires a string"))
    dm = util.matchdate(ds)
    return [r for r in subset if dm(repo[r].date()[0])]

def keyword(repo, subset, x):
    """``keyword(string)``
    Search commit message, user name, and names of changed files for
    string.
    """
    # i18n: "keyword" is a keyword
    kw = getstring(x, _("keyword requires a string")).lower()
    l = []
    for r in subset:
        c = repo[r]
        t = " ".join(c.files() + [c.user(), c.description()])
        if kw in t.lower():
            l.append(r)
    return l

def grep(repo, subset, x):
    """``grep(regex)``
    Like ``keyword(string)`` but accepts a regex. Use ``grep(r'...')``
    to ensure special escape characters are handled correctly.
    """
    try:
        # i18n: "grep" is a keyword
        gr = re.compile(getstring(x, _("grep requires a string")))
    except re.error, e:
        raise error.ParseError(_('invalid match pattern: %s') % e)
    l = []
    for r in subset:
        c = repo[r]
        for e in c.files() + [c.user(), c.description()]:
            if gr.search(e):
                l.append(r)
                continue
    return l

def author(repo, subset, x):
    """``author(string)``
    Alias for ``user(string)``.
    """
    # i18n: "author" is a keyword
    n = getstring(x, _("author requires a string")).lower()
    return [r for r in subset if n in repo[r].user().lower()]

def user(repo, subset, x):
    """``user(string)``
    User name is string.
    """
    return author(repo, subset, x)

def hasfile(repo, subset, x):
    """``file(pattern)``
    Changesets affecting files matched by pattern.
    """
    # i18n: "file" is a keyword
    pat = getstring(x, _("file requires a pattern"))
    m = matchmod.match(repo.root, repo.getcwd(), [pat])
    s = []
    for r in subset:
        for f in repo[r].files():
            if m(f):
                s.append(r)
                continue
    return s

def contains(repo, subset, x):
    """``contains(pattern)``
    Revision contains pattern.
    """
    # i18n: "contains" is a keyword
    pat = getstring(x, _("contains requires a pattern"))
    m = matchmod.match(repo.root, repo.getcwd(), [pat])
    s = []
    if m.files() == [pat]:
        for r in subset:
            if pat in repo[r]:
                s.append(r)
                continue
    else:
        for r in subset:
            for f in repo[r].manifest():
                if m(f):
                    s.append(r)
                    continue
    return s

def checkstatus(repo, subset, pat, field):
    m = matchmod.match(repo.root, repo.getcwd(), [pat])
    s = []
    fast = (m.files() == [pat])
    for r in subset:
        c = repo[r]
        if fast:
            if pat not in c.files():
                continue
        else:
            for f in c.files():
                if m(f):
                    break
            else:
                continue
        files = repo.status(c.p1().node(), c.node())[field]
        if fast:
            if pat in files:
                s.append(r)
                continue
        else:
            for f in files:
                if m(f):
                    s.append(r)
                    continue
    return s

def modifies(repo, subset, x):
    """``modifies(pattern)``
    Changesets modifying files matched by pattern.
    """
    # i18n: "modifies" is a keyword
    pat = getstring(x, _("modifies requires a pattern"))
    return checkstatus(repo, subset, pat, 0)

def adds(repo, subset, x):
    """``adds(pattern)``
    Changesets that add a file matching pattern.
    """
    # i18n: "adds" is a keyword
    pat = getstring(x, _("adds requires a pattern"))
    return checkstatus(repo, subset, pat, 1)

def removes(repo, subset, x):
    """``removes(pattern)``
    Changesets which remove files matching pattern.
    """
    # i18n: "removes" is a keyword
    pat = getstring(x, _("removes requires a pattern"))
    return checkstatus(repo, subset, pat, 2)

def merge(repo, subset, x):
    """``merge()``
    Changeset is a merge changeset.
    """
    # i18n: "merge" is a keyword
    getargs(x, 0, 0, _("merge takes no arguments"))
    cl = repo.changelog
    return [r for r in subset if cl.parentrevs(r)[1] != -1]

def closed(repo, subset, x):
    """``closed()``
    Changeset is closed.
    """
    # i18n: "closed" is a keyword
    getargs(x, 0, 0, _("closed takes no arguments"))
    return [r for r in subset if repo[r].extra().get('close')]

def head(repo, subset, x):
    """``head()``
    Changeset is a named branch head.
    """
    # i18n: "head" is a keyword
    getargs(x, 0, 0, _("head takes no arguments"))
    hs = set()
    for b, ls in repo.branchmap().iteritems():
        hs.update(repo[h].rev() for h in ls)
    return [r for r in subset if r in hs]

def reverse(repo, subset, x):
    """``reverse(set)``
    Reverse order of set.
    """
    l = getset(repo, subset, x)
    l.reverse()
    return l

def present(repo, subset, x):
    """``present(set)``
    An empty set, if any revision in set isn't found; otherwise,
    all revisions in set.
    """
    try:
        return getset(repo, subset, x)
    except error.RepoLookupError:
        return []

def sort(repo, subset, x):
    """``sort(set[, [-]key...])``
    Sort set by keys. The default sort order is ascending, specify a key
    as ``-key`` to sort in descending order.

    The keys can be:

    - ``rev`` for the revision number,
    - ``branch`` for the branch name,
    - ``desc`` for the commit message (description),
    - ``user`` for user name (``author`` can be used as an alias),
    - ``date`` for the commit date
    """
    # i18n: "sort" is a keyword
    l = getargs(x, 1, 2, _("sort requires one or two arguments"))
    keys = "rev"
    if len(l) == 2:
        keys = getstring(l[1], _("sort spec must be a string"))

    s = l[0]
    keys = keys.split()
    l = []
    def invert(s):
        return "".join(chr(255 - ord(c)) for c in s)
    for r in getset(repo, subset, s):
        c = repo[r]
        e = []
        for k in keys:
            if k == 'rev':
                e.append(r)
            elif k == '-rev':
                e.append(-r)
            elif k == 'branch':
                e.append(c.branch())
            elif k == '-branch':
                e.append(invert(c.branch()))
            elif k == 'desc':
                e.append(c.description())
            elif k == '-desc':
                e.append(invert(c.description()))
            elif k in 'user author':
                e.append(c.user())
            elif k in '-user -author':
                e.append(invert(c.user()))
            elif k == 'date':
                e.append(c.date()[0])
            elif k == '-date':
                e.append(-c.date()[0])
            else:
                raise error.ParseError(_("unknown sort key %r") % k)
        e.append(r)
        l.append(e)
    l.sort()
    return [e[-1] for e in l]

def getall(repo, subset, x):
    """``all()``
    All changesets, the same as ``0:tip``.
    """
    # i18n: "all" is a keyword
    getargs(x, 0, 0, _("all takes no arguments"))
    return subset

def heads(repo, subset, x):
    """``heads(set)``
    Members of set with no children in set.
    """
    s = getset(repo, subset, x)
    ps = set(parents(repo, subset, x))
    return [r for r in s if r not in ps]

def roots(repo, subset, x):
    """``roots(set)``
    Changesets with no parent changeset in set.
    """
    s = getset(repo, subset, x)
    cs = set(children(repo, subset, x))
    return [r for r in s if r not in cs]

def outgoing(repo, subset, x):
    """``outgoing([path])``
    Changesets not found in the specified destination repository, or the
    default push location.
    """
    import hg # avoid start-up nasties
    # i18n: "outgoing" is a keyword
    l = getargs(x, 0, 1, _("outgoing requires a repository path"))
    # i18n: "outgoing" is a keyword
    dest = l and getstring(l[0], _("outgoing requires a repository path")) or ''
    dest = repo.ui.expandpath(dest or 'default-push', dest or 'default')
    dest, branches = hg.parseurl(dest)
    revs, checkout = hg.addbranchrevs(repo, repo, branches, [])
    if revs:
        revs = [repo.lookup(rev) for rev in revs]
    other = hg.repository(hg.remoteui(repo, {}), dest)
    repo.ui.pushbuffer()
    o = discovery.findoutgoing(repo, other)
    repo.ui.popbuffer()
    cl = repo.changelog
    o = set([cl.rev(r) for r in repo.changelog.nodesbetween(o, revs)[0]])
    return [r for r in subset if r in o]

def tag(repo, subset, x):
    """``tag(name)``
    The specified tag by name, or all tagged revisions if no name is given.
    """
    # i18n: "tag" is a keyword
    args = getargs(x, 0, 1, _("tag takes one or no arguments"))
    cl = repo.changelog
    if args:
        tn = getstring(args[0],
                       # i18n: "tag" is a keyword
                       _('the argument to tag must be a string'))
        s = set([cl.rev(n) for t, n in repo.tagslist() if t == tn])
    else:
        s = set([cl.rev(n) for t, n in repo.tagslist() if t != 'tip'])
    return [r for r in subset if r in s]

def tagged(repo, subset, x):
    return tag(repo, subset, x)

symbols = {
    "adds": adds,
    "all": getall,
    "ancestor": ancestor,
    "ancestors": ancestors,
    "author": author,
    "branch": branch,
    "children": children,
    "closed": closed,
    "contains": contains,
    "date": date,
    "descendants": descendants,
    "file": hasfile,
    "follow": follow,
    "grep": grep,
    "head": head,
    "heads": heads,
    "keyword": keyword,
    "limit": limit,
    "max": maxrev,
    "min": minrev,
    "merge": merge,
    "modifies": modifies,
    "id": node,
    "outgoing": outgoing,
    "p1": p1,
    "p2": p2,
    "parents": parents,
    "present": present,
    "removes": removes,
    "reverse": reverse,
    "rev": rev,
    "roots": roots,
    "sort": sort,
    "tag": tag,
    "tagged": tagged,
    "user": user,
}

methods = {
    "range": rangeset,
    "string": stringset,
    "symbol": symbolset,
    "and": andset,
    "or": orset,
    "not": notset,
    "list": listset,
    "func": func,
}

def optimize(x, small):
    if x is None:
        return 0, x

    smallbonus = 1
    if small:
        smallbonus = .5

    op = x[0]
    if op == 'minus':
        return optimize(('and', x[1], ('not', x[2])), small)
    elif op == 'dagrange':
        return optimize(('and', ('func', ('symbol', 'descendants'), x[1]),
                         ('func', ('symbol', 'ancestors'), x[2])), small)
    elif op == 'dagrangepre':
        return optimize(('func', ('symbol', 'ancestors'), x[1]), small)
    elif op == 'dagrangepost':
        return optimize(('func', ('symbol', 'descendants'), x[1]), small)
    elif op == 'rangepre':
        return optimize(('range', ('string', '0'), x[1]), small)
    elif op == 'rangepost':
        return optimize(('range', x[1], ('string', 'tip')), small)
    elif op == 'negate':
        return optimize(('string',
                         '-' + getstring(x[1], _("can't negate that"))), small)
    elif op in 'string symbol negate':
        return smallbonus, x # single revisions are small
    elif op == 'and' or op == 'dagrange':
        wa, ta = optimize(x[1], True)
        wb, tb = optimize(x[2], True)
        w = min(wa, wb)
        if wa > wb:
            return w, (op, tb, ta)
        return w, (op, ta, tb)
    elif op == 'or':
        wa, ta = optimize(x[1], False)
        wb, tb = optimize(x[2], False)
        if wb < wa:
            wb, wa = wa, wb
        return max(wa, wb), (op, ta, tb)
    elif op == 'not':
        o = optimize(x[1], not small)
        return o[0], (op, o[1])
    elif op == 'group':
        return optimize(x[1], small)
    elif op in 'range list':
        wa, ta = optimize(x[1], small)
        wb, tb = optimize(x[2], small)
        return wa + wb, (op, ta, tb)
    elif op == 'func':
        f = getstring(x[1], _("not a symbol"))
        wa, ta = optimize(x[2], small)
        if f in "grep date user author keyword branch file outgoing":
            w = 10 # slow
        elif f in "modifies adds removes":
            w = 30 # slower
        elif f == "contains":
            w = 100 # very slow
        elif f == "ancestor":
            w = 1 * smallbonus
        elif f == "reverse limit":
            w = 0
        elif f in "sort":
            w = 10 # assume most sorts look at changelog
        else:
            w = 1
        return w + wa, (op, x[1], ta)
    return 1, x

parse = parser.parser(tokenize, elements).parse

def match(spec):
    if not spec:
        raise error.ParseError(_("empty query"))
    tree = parse(spec)
    weight, tree = optimize(tree, True)
    def mfunc(repo, subset):
        return getset(repo, subset, tree)
    return mfunc

def makedoc(topic, doc):
    """Generate and include predicates help in revsets topic."""
    predicates = []
    for name in sorted(symbols):
        text = symbols[name].__doc__
        if not text:
            continue
        text = gettext(text.rstrip())
        lines = text.splitlines()
        lines[1:] = [('  ' + l.strip()) for l in lines[1:]]
        predicates.append('\n'.join(lines))
    predicates = '\n\n'.join(predicates)
    doc = doc.replace('.. predicatesmarker', predicates)
    return doc

# tell hggettext to extract docstrings from these functions:
i18nfunctions = symbols.values()