view tests/test-wsgirequest.py @ 46607:e9901d01d135

revlog: add a mechanism to verify expected file position before appending

If someone uses `hg debuglocks`, or some non-hg process writes to the .hg
directory without respecting the locks, or if the repo's on a networked
filesystem, it's possible for the revlog code to write out corrupted data.

The form of this corruption can vary depending on what data was written and how
that happened. We are in the "networked filesystem" case (though I've had users
also do this to themselves with the "`hg debuglocks`" scenario), and most often
see this with the changelog. What ends up happening is we produce two items
(let's call them rev1 and rev2) in the .i file that have the same linkrev,
baserev, and offset into the .d file, while the data in the .d file is appended
properly. rev2's compressed_size is accurate for rev2, but when we go to
decompress the data in the .d file, we use the offset that's recorded in the
index file, which is the same as rev1, and attempt to decompress
rev2.compressed_size bytes of rev1's data. This usually does not succeed. :)

When using inline data, this also fails, though I haven't investigated why too
closely. This shows up as a "patch decode" error. I believe what's happening
there is that we're basically ignoring the offset field, getting the data
properly, but since baserev != rev, it thinks this is a delta based on rev
(instead of a full text) and can't actually apply it as such.

For now, I'm going to make this an optional component and default it to entirely
off. I may increase the default severity of this in the future, once I've
enabled it for my users and we gain more experience with it. Luckily, most of my
users have a versioned filesystem and can roll back to before the corruption has
been written, it's just a hassle to do so and not everyone knows how (so it's a
support burden). Users on other filesystems will not have that luxury, and this
can cause them to have a corrupted repository that they are unlikely to know how
to resolve, and they'll see this as a data-loss event. Refusing to create the
corruption is a much better user experience.

This mechanism is not perfect. There may be false-negatives (racy writes that
are not detected). There should not be any false-positives (non-racy writes that
are detected as such). This is not a mechanism that makes putting a repo on a
networked filesystem "safe" or "supported", just *less* likely to cause
corruption.

Differential Revision: https://phab.mercurial-scm.org/D9952

from __future__ import absolute_import, print_function

import unittest

from mercurial.hgweb import request as requestmod
from mercurial import error, pycompat

DEFAULT_ENV = {
    'REQUEST_METHOD': 'GET',
    'SERVER_NAME': 'testserver',
    'SERVER_PORT': '80',
    'SERVER_PROTOCOL': 'http',
    'wsgi.version': (1, 0),
    'wsgi.url_scheme': 'http',
    'wsgi.input': None,
    'wsgi.errors': None,
    'wsgi.multithread': False,
    'wsgi.multiprocess': True,
    'wsgi.run_once': False,
}


def parse(env, reponame=None, altbaseurl=None, extra=None):
    env = dict(env)
    env.update(extra or {})

    return requestmod.parserequestfromenv(
        env, reponame=reponame, altbaseurl=altbaseurl
    )


class ParseRequestTests(unittest.TestCase):
    def testdefault(self):
        r = parse(DEFAULT_ENV)
        self.assertEqual(r.url, b'http://testserver')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(r.advertisedurl, b'http://testserver')
        self.assertEqual(r.advertisedbaseurl, b'http://testserver')
        self.assertEqual(r.urlscheme, b'http')
        self.assertEqual(r.method, b'GET')
        self.assertIsNone(r.remoteuser)
        self.assertIsNone(r.remotehost)
        self.assertEqual(r.apppath, b'')
        self.assertEqual(r.dispatchparts, [])
        self.assertIsNone(r.dispatchpath)
        self.assertIsNone(r.reponame)
        self.assertEqual(r.querystring, b'')
        self.assertEqual(len(r.qsparams), 0)
        self.assertEqual(len(r.headers), 0)

    def testcustomport(self):
        r = parse(
            DEFAULT_ENV,
            extra={
                'SERVER_PORT': '8000',
            },
        )

        self.assertEqual(r.url, b'http://testserver:8000')
        self.assertEqual(r.baseurl, b'http://testserver:8000')
        self.assertEqual(r.advertisedurl, b'http://testserver:8000')
        self.assertEqual(r.advertisedbaseurl, b'http://testserver:8000')

        r = parse(
            DEFAULT_ENV,
            extra={
                'SERVER_PORT': '4000',
                'wsgi.url_scheme': 'https',
            },
        )

        self.assertEqual(r.url, b'https://testserver:4000')
        self.assertEqual(r.baseurl, b'https://testserver:4000')
        self.assertEqual(r.advertisedurl, b'https://testserver:4000')
        self.assertEqual(r.advertisedbaseurl, b'https://testserver:4000')

    def testhttphost(self):
        r = parse(
            DEFAULT_ENV,
            extra={
                'HTTP_HOST': 'altserver',
            },
        )

        self.assertEqual(r.url, b'http://altserver')
        self.assertEqual(r.baseurl, b'http://altserver')
        self.assertEqual(r.advertisedurl, b'http://testserver')
        self.assertEqual(r.advertisedbaseurl, b'http://testserver')

    def testscriptname(self):
        r = parse(
            DEFAULT_ENV,
            extra={
                'SCRIPT_NAME': '',
            },
        )

        self.assertEqual(r.url, b'http://testserver')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(r.advertisedurl, b'http://testserver')
        self.assertEqual(r.advertisedbaseurl, b'http://testserver')
        self.assertEqual(r.apppath, b'')
        self.assertEqual(r.dispatchparts, [])
        self.assertIsNone(r.dispatchpath)

        r = parse(
            DEFAULT_ENV,
            extra={
                'SCRIPT_NAME': '/script',
            },
        )

        self.assertEqual(r.url, b'http://testserver/script')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(r.advertisedurl, b'http://testserver/script')
        self.assertEqual(r.advertisedbaseurl, b'http://testserver')
        self.assertEqual(r.apppath, b'/script')
        self.assertEqual(r.dispatchparts, [])
        self.assertIsNone(r.dispatchpath)

        r = parse(
            DEFAULT_ENV,
            extra={
                'SCRIPT_NAME': '/multiple words',
            },
        )

        self.assertEqual(r.url, b'http://testserver/multiple%20words')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(r.advertisedurl, b'http://testserver/multiple%20words')
        self.assertEqual(r.advertisedbaseurl, b'http://testserver')
        self.assertEqual(r.apppath, b'/multiple words')
        self.assertEqual(r.dispatchparts, [])
        self.assertIsNone(r.dispatchpath)

    def testpathinfo(self):
        r = parse(
            DEFAULT_ENV,
            extra={
                'PATH_INFO': '',
            },
        )

        self.assertEqual(r.url, b'http://testserver')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(r.advertisedurl, b'http://testserver')
        self.assertEqual(r.advertisedbaseurl, b'http://testserver')
        self.assertEqual(r.apppath, b'')
        self.assertEqual(r.dispatchparts, [])
        self.assertEqual(r.dispatchpath, b'')

        r = parse(
            DEFAULT_ENV,
            extra={
                'PATH_INFO': '/pathinfo',
            },
        )

        self.assertEqual(r.url, b'http://testserver/pathinfo')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(r.advertisedurl, b'http://testserver/pathinfo')
        self.assertEqual(r.advertisedbaseurl, b'http://testserver')
        self.assertEqual(r.apppath, b'')
        self.assertEqual(r.dispatchparts, [b'pathinfo'])
        self.assertEqual(r.dispatchpath, b'pathinfo')

        r = parse(
            DEFAULT_ENV,
            extra={
                'PATH_INFO': '/one/two/',
            },
        )

        self.assertEqual(r.url, b'http://testserver/one/two/')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(r.advertisedurl, b'http://testserver/one/two/')
        self.assertEqual(r.advertisedbaseurl, b'http://testserver')
        self.assertEqual(r.apppath, b'')
        self.assertEqual(r.dispatchparts, [b'one', b'two'])
        self.assertEqual(r.dispatchpath, b'one/two')

    def testscriptandpathinfo(self):
        r = parse(
            DEFAULT_ENV,
            extra={
                'SCRIPT_NAME': '/script',
                'PATH_INFO': '/pathinfo',
            },
        )

        self.assertEqual(r.url, b'http://testserver/script/pathinfo')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(r.advertisedurl, b'http://testserver/script/pathinfo')
        self.assertEqual(r.advertisedbaseurl, b'http://testserver')
        self.assertEqual(r.apppath, b'/script')
        self.assertEqual(r.dispatchparts, [b'pathinfo'])
        self.assertEqual(r.dispatchpath, b'pathinfo')

        r = parse(
            DEFAULT_ENV,
            extra={
                'SCRIPT_NAME': '/script1/script2',
                'PATH_INFO': '/path1/path2',
            },
        )

        self.assertEqual(
            r.url, b'http://testserver/script1/script2/path1/path2'
        )
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(
            r.advertisedurl, b'http://testserver/script1/script2/path1/path2'
        )
        self.assertEqual(r.advertisedbaseurl, b'http://testserver')
        self.assertEqual(r.apppath, b'/script1/script2')
        self.assertEqual(r.dispatchparts, [b'path1', b'path2'])
        self.assertEqual(r.dispatchpath, b'path1/path2')

        r = parse(
            DEFAULT_ENV,
            extra={
                'HTTP_HOST': 'hostserver',
                'SCRIPT_NAME': '/script',
                'PATH_INFO': '/pathinfo',
            },
        )

        self.assertEqual(r.url, b'http://hostserver/script/pathinfo')
        self.assertEqual(r.baseurl, b'http://hostserver')
        self.assertEqual(r.advertisedurl, b'http://testserver/script/pathinfo')
        self.assertEqual(r.advertisedbaseurl, b'http://testserver')
        self.assertEqual(r.apppath, b'/script')
        self.assertEqual(r.dispatchparts, [b'pathinfo'])
        self.assertEqual(r.dispatchpath, b'pathinfo')

    if not getattr(unittest.TestCase, 'assertRaisesRegex', False):
        # Python 3.7 deprecates the regex*p* version, but 2.7 lacks
        # the regex version.
        assertRaisesRegex = (  # camelcase-required
            unittest.TestCase.assertRaisesRegexp
        )

    def testreponame(self):
        """repository path components get stripped from URL."""

        with self.assertRaisesRegex(
            error.ProgrammingError, 'reponame requires PATH_INFO'
        ):
            parse(DEFAULT_ENV, reponame=b'repo')

        with self.assertRaisesRegex(
            error.ProgrammingError, 'PATH_INFO does not begin with repo ' 'name'
        ):
            parse(
                DEFAULT_ENV,
                reponame=b'repo',
                extra={
                    'PATH_INFO': '/pathinfo',
                },
            )

        with self.assertRaisesRegex(
            error.ProgrammingError, 'reponame prefix of PATH_INFO'
        ):
            parse(
                DEFAULT_ENV,
                reponame=b'repo',
                extra={
                    'PATH_INFO': '/repoextra/path',
                },
            )

        r = parse(
            DEFAULT_ENV,
            reponame=b'repo',
            extra={
                'PATH_INFO': '/repo/path1/path2',
            },
        )

        self.assertEqual(r.url, b'http://testserver/repo/path1/path2')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(r.advertisedurl, b'http://testserver/repo/path1/path2')
        self.assertEqual(r.advertisedbaseurl, b'http://testserver')
        self.assertEqual(r.apppath, b'/repo')
        self.assertEqual(r.dispatchparts, [b'path1', b'path2'])
        self.assertEqual(r.dispatchpath, b'path1/path2')
        self.assertEqual(r.reponame, b'repo')

        r = parse(
            DEFAULT_ENV,
            reponame=b'prefix/repo',
            extra={
                'PATH_INFO': '/prefix/repo/path1/path2',
            },
        )

        self.assertEqual(r.url, b'http://testserver/prefix/repo/path1/path2')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(
            r.advertisedurl, b'http://testserver/prefix/repo/path1/path2'
        )
        self.assertEqual(r.advertisedbaseurl, b'http://testserver')
        self.assertEqual(r.apppath, b'/prefix/repo')
        self.assertEqual(r.dispatchparts, [b'path1', b'path2'])
        self.assertEqual(r.dispatchpath, b'path1/path2')
        self.assertEqual(r.reponame, b'prefix/repo')

    def testaltbaseurl(self):
        # Simple hostname remap.
        r = parse(DEFAULT_ENV, altbaseurl=b'http://altserver')

        self.assertEqual(r.url, b'http://testserver')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(r.advertisedurl, b'http://altserver')
        self.assertEqual(r.advertisedbaseurl, b'http://altserver')
        self.assertEqual(r.urlscheme, b'http')
        self.assertEqual(r.apppath, b'')
        self.assertEqual(r.dispatchparts, [])
        self.assertIsNone(r.dispatchpath)
        self.assertIsNone(r.reponame)

        # With a custom port.
        r = parse(DEFAULT_ENV, altbaseurl=b'http://altserver:8000')
        self.assertEqual(r.url, b'http://testserver')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(r.advertisedurl, b'http://altserver:8000')
        self.assertEqual(r.advertisedbaseurl, b'http://altserver:8000')
        self.assertEqual(r.urlscheme, b'http')
        self.assertEqual(r.apppath, b'')
        self.assertEqual(r.dispatchparts, [])
        self.assertIsNone(r.dispatchpath)
        self.assertIsNone(r.reponame)

        # With a changed protocol.
        r = parse(DEFAULT_ENV, altbaseurl=b'https://altserver')
        self.assertEqual(r.url, b'http://testserver')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(r.advertisedurl, b'https://altserver')
        self.assertEqual(r.advertisedbaseurl, b'https://altserver')
        # URL scheme is defined as the actual scheme, not advertised.
        self.assertEqual(r.urlscheme, b'http')
        self.assertEqual(r.apppath, b'')
        self.assertEqual(r.dispatchparts, [])
        self.assertIsNone(r.dispatchpath)
        self.assertIsNone(r.reponame)

        # Need to specify explicit port number for proper https:// alt URLs.
        r = parse(DEFAULT_ENV, altbaseurl=b'https://altserver:443')
        self.assertEqual(r.url, b'http://testserver')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(r.advertisedurl, b'https://altserver')
        self.assertEqual(r.advertisedbaseurl, b'https://altserver')
        self.assertEqual(r.urlscheme, b'http')
        self.assertEqual(r.apppath, b'')
        self.assertEqual(r.dispatchparts, [])
        self.assertIsNone(r.dispatchpath)
        self.assertIsNone(r.reponame)

        # With only PATH_INFO defined.
        r = parse(
            DEFAULT_ENV,
            altbaseurl=b'http://altserver',
            extra={
                'PATH_INFO': '/path1/path2',
            },
        )
        self.assertEqual(r.url, b'http://testserver/path1/path2')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(r.advertisedurl, b'http://altserver/path1/path2')
        self.assertEqual(r.advertisedbaseurl, b'http://altserver')
        self.assertEqual(r.urlscheme, b'http')
        self.assertEqual(r.apppath, b'')
        self.assertEqual(r.dispatchparts, [b'path1', b'path2'])
        self.assertEqual(r.dispatchpath, b'path1/path2')
        self.assertIsNone(r.reponame)

        # Path on alt URL.
        r = parse(DEFAULT_ENV, altbaseurl=b'http://altserver/altpath')
        self.assertEqual(r.url, b'http://testserver')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(r.advertisedurl, b'http://altserver/altpath')
        self.assertEqual(r.advertisedbaseurl, b'http://altserver')
        self.assertEqual(r.urlscheme, b'http')
        self.assertEqual(r.apppath, b'/altpath')
        self.assertEqual(r.dispatchparts, [])
        self.assertIsNone(r.dispatchpath)
        self.assertIsNone(r.reponame)

        # With a trailing slash.
        r = parse(DEFAULT_ENV, altbaseurl=b'http://altserver/altpath/')
        self.assertEqual(r.url, b'http://testserver')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(r.advertisedurl, b'http://altserver/altpath/')
        self.assertEqual(r.advertisedbaseurl, b'http://altserver')
        self.assertEqual(r.urlscheme, b'http')
        self.assertEqual(r.apppath, b'/altpath/')
        self.assertEqual(r.dispatchparts, [])
        self.assertIsNone(r.dispatchpath)
        self.assertIsNone(r.reponame)

        # PATH_INFO + path on alt URL.
        r = parse(
            DEFAULT_ENV,
            altbaseurl=b'http://altserver/altpath',
            extra={
                'PATH_INFO': '/path1/path2',
            },
        )
        self.assertEqual(r.url, b'http://testserver/path1/path2')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(
            r.advertisedurl, b'http://altserver/altpath/path1/path2'
        )
        self.assertEqual(r.advertisedbaseurl, b'http://altserver')
        self.assertEqual(r.urlscheme, b'http')
        self.assertEqual(r.apppath, b'/altpath')
        self.assertEqual(r.dispatchparts, [b'path1', b'path2'])
        self.assertEqual(r.dispatchpath, b'path1/path2')
        self.assertIsNone(r.reponame)

        # PATH_INFO + path on alt URL with trailing slash.
        r = parse(
            DEFAULT_ENV,
            altbaseurl=b'http://altserver/altpath/',
            extra={
                'PATH_INFO': '/path1/path2',
            },
        )
        self.assertEqual(r.url, b'http://testserver/path1/path2')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(
            r.advertisedurl, b'http://altserver/altpath//path1/path2'
        )
        self.assertEqual(r.advertisedbaseurl, b'http://altserver')
        self.assertEqual(r.urlscheme, b'http')
        self.assertEqual(r.apppath, b'/altpath/')
        self.assertEqual(r.dispatchparts, [b'path1', b'path2'])
        self.assertEqual(r.dispatchpath, b'path1/path2')
        self.assertIsNone(r.reponame)

        # Local SCRIPT_NAME is ignored.
        r = parse(
            DEFAULT_ENV,
            altbaseurl=b'http://altserver',
            extra={
                'SCRIPT_NAME': '/script',
                'PATH_INFO': '/path1/path2',
            },
        )
        self.assertEqual(r.url, b'http://testserver/script/path1/path2')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(r.advertisedurl, b'http://altserver/path1/path2')
        self.assertEqual(r.advertisedbaseurl, b'http://altserver')
        self.assertEqual(r.urlscheme, b'http')
        self.assertEqual(r.apppath, b'')
        self.assertEqual(r.dispatchparts, [b'path1', b'path2'])
        self.assertEqual(r.dispatchpath, b'path1/path2')
        self.assertIsNone(r.reponame)

        # Use remote's path for script name, app path
        r = parse(
            DEFAULT_ENV,
            altbaseurl=b'http://altserver/altroot',
            extra={
                'SCRIPT_NAME': '/script',
                'PATH_INFO': '/path1/path2',
            },
        )
        self.assertEqual(r.url, b'http://testserver/script/path1/path2')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(
            r.advertisedurl, b'http://altserver/altroot/path1/path2'
        )
        self.assertEqual(r.advertisedbaseurl, b'http://altserver')
        self.assertEqual(r.urlscheme, b'http')
        self.assertEqual(r.apppath, b'/altroot')
        self.assertEqual(r.dispatchparts, [b'path1', b'path2'])
        self.assertEqual(r.dispatchpath, b'path1/path2')
        self.assertIsNone(r.reponame)

        # reponame is factored in properly.
        r = parse(
            DEFAULT_ENV,
            reponame=b'repo',
            altbaseurl=b'http://altserver/altroot',
            extra={
                'SCRIPT_NAME': '/script',
                'PATH_INFO': '/repo/path1/path2',
            },
        )

        self.assertEqual(r.url, b'http://testserver/script/repo/path1/path2')
        self.assertEqual(r.baseurl, b'http://testserver')
        self.assertEqual(
            r.advertisedurl, b'http://altserver/altroot/repo/path1/path2'
        )
        self.assertEqual(r.advertisedbaseurl, b'http://altserver')
        self.assertEqual(r.apppath, b'/altroot/repo')
        self.assertEqual(r.dispatchparts, [b'path1', b'path2'])
        self.assertEqual(r.dispatchpath, b'path1/path2')
        self.assertEqual(r.reponame, b'repo')

    def testenvencoding(self):
        if pycompat.iswindows:
            # On Windows, we can't generally know which non-ASCII characters
            # are supported.
            r = parse(DEFAULT_ENV, extra={'foo': 'bar'})
            self.assertEqual(r.rawenv[b'foo'], b'bar')
        else:
            # Unix is byte-based. Therefore we test all possible bytes.
            b = b''.join(pycompat.bytechr(i) for i in range(256))
            r = parse(DEFAULT_ENV, extra={'foo': pycompat.fsdecode(b)})
            self.assertEqual(r.rawenv[b'foo'], b)


if __name__ == '__main__':
    import silenttestrunner

    silenttestrunner.main(__name__)