view hgext/censor.py @ 45217:4e5da64d5549

tests: make check-py3-compat.py actually load the specified files correctly

For most uses, this change is essentially a no-op, as this script is generally
only run by test-check-py3-compat.t, which will already put `$TESTDIR/..` in
`$PYTHONPATH`.

When running outside of tests, however, `$PYTHONPATH` is likely not set, causing
check-py3-compat.py to parse the file from the repo, but then import the
installed version, and raise any errors about the installed version, not the one
currently in the repo.

Additionally, this helps users (like me) who have a strange set up where their
home directory (and thus their hg repos) happen to be in a subdirectory of
sys.prefix (which is /usr on my system). Since the '.' entry added to sys.path
takes precedence over the absolute path of `$TESTDIR/..` in `$PYTHONPATH`, the
path to the modules that it imports (and that show up in any stack trace) are
*relative*, meaning that we don't detect them as starting with `sys.prefix`.

Sample non-test invocation, and the difference this change makes (the path for
'error at <path>:<line>' is correct now)::

Before:
```
$ python3 contrib/check-py3-compat.py mercurial/win*.py
mercurial/win32.py: error importing: <ValueError> _type_ 'v' not supported (error at check-py3-compat.py:65)
mercurial/windows.py: error importing: <ModuleNotFoundError> No module named 'msvcrt' (error at check-py3-compat.py:65)
```

After:
```
$ python3 contrib/check-py3-compat.py mercurial/win*.py
mercurial/win32.py: error importing: <ValueError> _type_ 'v' not supported (error at win32.py:11)
mercurial/windows.py: error importing: <ModuleNotFoundError> No module named 'msvcrt' (error at windows.py:12)
```

Differential Revision: https://phab.mercurial-scm.org/D8814

# Copyright (C) 2015 - Mike Edgar <[e-mail]>
#
# This extension enables removal of file content at a given revision,
# rewriting the data/metadata of successive revisions to preserve revision log
# integrity.

"""erase file content at a given revision

The censor command instructs Mercurial to erase all content of a file at a given
revision *without updating the changeset hash.* This allows existing history to
remain valid while preventing future clones/pulls from receiving the erased
data.

Typical uses for censor are due to security or legal requirements, including::

 * Passwords, private keys, cryptographic material
 * Licensed data/code/libraries for which the license has expired
 * Personally Identifiable Information or other private data

Censored nodes can interrupt mercurial's typical operation whenever the excised
data needs to be materialized. Some commands, like ``hg cat``/``hg revert``,
simply fail when asked to produce censored data. Others, like ``hg verify`` and
``hg update``, must be capable of tolerating censored data to continue to
function in a meaningful way. Such commands only tolerate censored file
revisions if they are allowed by the "censor.policy=ignore" config option.

A few informative commands such as ``hg grep`` will unconditionally
ignore censored data and merely report that it was encountered.
"""

from __future__ import absolute_import

from mercurial.i18n import _
from mercurial.node import short

from mercurial import (
    error,
    registrar,
    scmutil,
)

cmdtable = {}
command = registrar.command(cmdtable)
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = b'ships-with-hg-core'


@command(
    b'censor',
    [
        (
            b'r',
            b'rev',
            b'',
            _(b'censor file from specified revision'),
            _(b'REV'),
        ),
        (b't', b'tombstone', b'', _(b'replacement tombstone data'), _(b'TEXT')),
    ],
    _(b'-r REV [-t TEXT] [FILE]'),
    helpcategory=command.CATEGORY_MAINTENANCE,
)
def censor(ui, repo, path, rev=b'', tombstone=b'', **opts):
    with repo.wlock(), repo.lock():
        return _docensor(ui, repo, path, rev, tombstone, **opts)


def _docensor(ui, repo, path, rev=b'', tombstone=b'', **opts):
    if not path:
        raise error.Abort(_(b'must specify file path to censor'))
    if not rev:
        raise error.Abort(_(b'must specify revision to censor'))

    wctx = repo[None]

    m = scmutil.match(wctx, (path,))
    if m.anypats() or len(m.files()) != 1:
        raise error.Abort(_(b'can only specify an explicit filename'))
    path = m.files()[0]
    flog = repo.file(path)
    if not len(flog):
        raise error.Abort(_(b'cannot censor file with no history'))

    rev = scmutil.revsingle(repo, rev, rev).rev()
    try:
        ctx = repo[rev]
    except KeyError:
        raise error.Abort(_(b'invalid revision identifier %s') % rev)

    try:
        fctx = ctx.filectx(path)
    except error.LookupError:
        raise error.Abort(_(b'file does not exist at revision %s') % rev)

    fnode = fctx.filenode()
    heads = []
    for headnode in repo.heads():
        hc = repo[headnode]
        if path in hc and hc.filenode(path) == fnode:
            heads.append(hc)
    if heads:
        headlist = b', '.join([short(c.node()) for c in heads])
        raise error.Abort(
            _(b'cannot censor file in heads (%s)') % headlist,
            hint=_(b'clean/delete and commit first'),
        )

    wp = wctx.parents()
    if ctx.node() in [p.node() for p in wp]:
        raise error.Abort(
            _(b'cannot censor working directory'),
            hint=_(b'clean/delete/update first'),
        )

    with repo.transaction(b'censor') as tr:
        flog.censorrevision(tr, fnode, tombstone=tombstone)