contrib/dirstatenonnormalcheck.py

hgdemandimport: disable on Python 3.5

The demand importer functionality isn't working at all on Python 3.5.
I'm not sure what's wrong.

Since it isn't working, let's disable it completely.

```
$ HGRCPATH= hyperfine -w 1 -r 50 -- "~/.pyenv/versions/3.5.9/bin/python ./hg version" \
  "HGDEMANDIMPORT=disable ~/.pyenv/versions/3.5.9/bin/python ./hg version"
Benchmark #1: ~/.pyenv/versions/3.5.9/bin/python ./hg version
  Time (mean ± σ):     163.7 ms ±   2.2 ms    [User: 148.5 ms, System: 15.7 ms]
  Range (min … max):   161.0 ms … 170.2 ms    50 runs

Benchmark #2: HGDEMANDIMPORT=disable ~/.pyenv/versions/3.5.9/bin/python ./hg version
  Time (mean ± σ):     164.3 ms ±   1.4 ms    [User: 148.2 ms, System: 16.6 ms]
  Range (min … max):   161.4 ms … 169.8 ms    50 runs
```

Differential Revision: https://phab.mercurial-scm.org/D7953

# dirstatenonnormalcheck.py - extension to check the consistency of the
# dirstate's non-normal map
#
# For most operations on dirstate, this extensions checks that the nonnormalset
# contains the right entries.
# It compares the nonnormal file to a nonnormalset built from the map of all
# the files in the dirstate to check that they contain the same files.

from __future__ import absolute_import

from mercurial import (
    dirstate,
    extensions,
)


def nonnormalentries(dmap):
    """Compute nonnormal entries from dirstate's dmap"""
    res = set()
    for f, e in dmap.iteritems():
        if e[0] != b'n' or e[3] == -1:
            res.add(f)
    return res


def checkconsistency(ui, orig, dmap, _nonnormalset, label):
    """Compute nonnormalset from dmap, check that it matches _nonnormalset"""
    nonnormalcomputedmap = nonnormalentries(dmap)
    if _nonnormalset != nonnormalcomputedmap:
        ui.develwarn(b"%s call to %s\n" % (label, orig), config=b'dirstate')
        ui.develwarn(b"inconsistency in nonnormalset\n", config=b'dirstate')
        ui.develwarn(b"[nonnormalset] %s\n" % _nonnormalset, config=b'dirstate')
        ui.develwarn(b"[map] %s\n" % nonnormalcomputedmap, config=b'dirstate')


def _checkdirstate(orig, self, arg):
    """Check nonnormal set consistency before and after the call to orig"""
    checkconsistency(
        self._ui, orig, self._map, self._map.nonnormalset, b"before"
    )
    r = orig(self, arg)
    checkconsistency(
        self._ui, orig, self._map, self._map.nonnormalset, b"after"
    )
    return r


def extsetup(ui):
    """Wrap functions modifying dirstate to check nonnormalset consistency"""
    dirstatecl = dirstate.dirstate
    devel = ui.configbool(b'devel', b'all-warnings')
    paranoid = ui.configbool(b'experimental', b'nonnormalparanoidcheck')
    if devel:
        extensions.wrapfunction(dirstatecl, '_writedirstate', _checkdirstate)
        if paranoid:
            # We don't do all these checks when paranoid is disable as it would
            # make the extension run very slowly on large repos
            extensions.wrapfunction(dirstatecl, 'normallookup', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'otherparent', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'normal', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'write', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'add', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'remove', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'merge', _checkdirstate)
            extensions.wrapfunction(dirstatecl, 'drop', _checkdirstate)