tests/logexceptions.py

tests: add test for issue5343 (grafting with copies)

It seems that issue5353 resulted in a lot of tests in test-graft.t,
but the bug actually reported in that issue didn't get a test
case. This patch adds one for the "move" and one for the "copy"
version of it. I also added a "copy+modify" case, to show what should
be a merge conflict. I didn't add one for the "backwards" version of
it since the comment says that that was already covered by previous
work.

The tests added by this patch show the broken behavior (the bug is
still open). I suspect the results returned from mergecopies() are not
expressive enough to fix this issue: it has a dict for copies to merge
with, but that can only give one more filename, but here we need two
(one for the path on the remote side and one for the path in the merge
base). I want to have it tested anyway since I'm about to refactor
mergecopies().

Differential Revision: https://phab.mercurial-scm.org/D6242

# logexceptions.py - Write files containing info about Mercurial exceptions
#
# Copyright 2017 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.

from __future__ import absolute_import

import inspect
import os
import sys
import traceback
import uuid

from mercurial import (
    dispatch,
    extensions,
)

def handleexception(orig, ui):
    res = orig(ui)

    if not ui.environ.get(b'HGEXCEPTIONSDIR'):
        return res

    dest = os.path.join(ui.environ[b'HGEXCEPTIONSDIR'],
                        str(uuid.uuid4()).encode('ascii'))

    exc_type, exc_value, exc_tb = sys.exc_info()

    stack = []
    tb = exc_tb
    while tb:
        stack.append(tb)
        tb = tb.tb_next
    stack.reverse()

    hgframe = 'unknown'
    hgline = 'unknown'

    # Find the first Mercurial frame in the stack.
    for tb in stack:
        mod = inspect.getmodule(tb)
        if not mod.__name__.startswith(('hg', 'mercurial')):
            continue

        frame = tb.tb_frame

        try:
            with open(inspect.getsourcefile(tb), 'r') as fh:
                hgline = fh.readlines()[frame.f_lineno - 1].strip()
        except (IndexError, OSError):
            pass

        hgframe = '%s:%d' % (frame.f_code.co_filename, frame.f_lineno)
        break

    primary = traceback.extract_tb(exc_tb)[-1]
    primaryframe = '%s:%d' % (primary.filename, primary.lineno)

    with open(dest, 'wb') as fh:
        parts = [
            str(exc_value),
            primaryframe,
            hgframe,
            hgline,
            ui.environ[b'TESTNAME'].decode('utf-8', 'replace'),
        ]
        fh.write(b'\0'.join(p.encode('utf-8', 'replace') for p in parts))

def extsetup(ui):
    extensions.wrapfunction(dispatch, 'handlecommandexception',
                            handleexception)