view contrib/debugcmdserver.py @ 44381:9c9cfecd4600

rebase: don't use rebased node as dirstate p2 (BC)

When rebasing a node, we currently use the rebased node as p2 in the
dirstate until just before we commit it (we then change to the desired
parents). This p2 is visible to the user when the rebase gets
interrupted because of merge conflicts. That can be useful to the user
as a reminder of which commit is currently being rebased, but I
believe it's incorrect for a few reasons:

 * I think the dirstate parents should be the ones that will be set
   when the commit is created.

 * I think having two parents means that you're merging those two
   commits, but when rebasing, you're generally grafting, not merging.

 * When rebasing a merge commit, we should use the two desired parents
   as dirstate parents (and we clearly can't have the rebased node as
   a third dirstate parent).

 * `hg graft` (and `hg update --merge`) sets only one parent and `hg
   rebase` should be consistent with that.

I realize that this is a somewhat large user-visible change, but I
think it's worth it because it will simplify things quite a bit.

Differential Revision: https://phab.mercurial-scm.org/D7827

#!/usr/bin/env python
#
# Dumps output generated by Mercurial's command server in a formatted style to a
# given file or stderr if '-' is specified. Output is also written in its raw
# format to stdout.
#
# $ ./hg serve --cmds pipe | ./contrib/debugcmdserver.py -
# o, 52   -> 'capabilities: getencoding runcommand\nencoding: UTF-8'

from __future__ import absolute_import, print_function
import struct
import sys

if len(sys.argv) != 2:
    print('usage: debugcmdserver.py FILE')
    sys.exit(1)

outputfmt = '>cI'
outputfmtsize = struct.calcsize(outputfmt)

if sys.argv[1] == '-':
    log = sys.stderr
else:
    log = open(sys.argv[1], 'a')


def read(size):
    data = sys.stdin.read(size)
    if not data:
        raise EOFError
    sys.stdout.write(data)
    sys.stdout.flush()
    return data


try:
    while True:
        header = read(outputfmtsize)
        channel, length = struct.unpack(outputfmt, header)
        log.write('%s, %-4d' % (channel, length))
        if channel in 'IL':
            log.write(' -> waiting for input\n')
        else:
            data = read(length)
            log.write(' -> %r\n' % data)
        log.flush()
except EOFError:
    pass
finally:
    if log != sys.stderr:
        log.close()