view tests/test-url.py @ 20742:3681de20b0a7

parsers: fail fast if Python has wrong minor version (issue4110)

This change causes an informative ImportError to be raised when importing
the parsers extension module if the minor version of the currently-running
Python interpreter doesn't match that of the Python used when compiling
the extension module.

This change also exposes a parsers.versionerrortext constant in the
C implementation of the module.  Its presence can be used to determine
whether this behavior is present in a version of the module.  The value
of the constant is the leading text of the ImportError raised and is set
to "Python minor version mismatch".

Here is an example of what the new error looks like:

  Traceback (most recent call last):
    File "test.py", line 1, in <module>
      import mercurial.parsers
  ImportError: Python minor version mismatch: The Mercurial extension
  modules were compiled with Python 2.7.6, but Mercurial is currently using
  Python with sys.hexversion=33883888: Python 2.5.6
  (r256:88840, Nov 18 2012, 05:37:10)
  [GCC 4.2.1 Compatible Apple Clang 4.1 ((tags/Apple/clang-421.11.66))]
   at: /opt/local/Library/Frameworks/Python.framework/Versions/2.5/Resources/
    Python.app/Contents/MacOS/Python

The reason for raising an error in this scenario is that Python's C API
is known not to be compatible from minor version to minor version, even
if sys.api_version is the same.  See for example this Python bug report
about incompatibilities between 2.5 and 2.6+:

  http://bugs.python.org/issue8118

These incompatibilities can cause Mercurial to break in mysterious,
unforeseen ways.  For example, when Mercurial compiled with Python 2.7 was
run with 2.5, the following crash occurred when running "hg status":

  http://bz.selenic.com/show_bug.cgi?id=4110

After this crash was fixed, running with Python 2.5 no longer crashes, but
the following puzzling behavior still occurs:

    $ hg status
      ...
      File ".../mercurial/changelog.py", line 123, in __init__
        revlog.revlog.__init__(self, opener, "00changelog.i")
      File ".../mercurial/revlog.py", line 251, in __init__
        d = self._io.parseindex(i, self._inline)
      File ".../mercurial/revlog.py", line 158, in parseindex
        index, cache = parsers.parse_index2(data, inline)
    TypeError: data is not a string

which can be reproduced more simply with:

    import mercurial.parsers as parsers
    parsers.parse_index2("", True)

Both the crash and the TypeError occurred because the Python C API's
PyString_Check() returns the wrong value when the C header files from
Python 2.7 are run with Python 2.5.  This is an example of an
incompatibility of the sort mentioned in the Python bug report above.

Failing fast with an informative error message results in a better user
experience in cases like the above.  The information in the ImportError
also simplifies troubleshooting for those on Mercurial mailing lists, the
bug tracker, etc.

This patch only adds the version check to parsers.c, which is sufficient
to affect command-line commands like "hg status" and "hg summary".
An idea for a future improvement is to move the version-checking C code
to a more central location, and have it run when importing all
Mercurial extension modules and not just parsers.c.

import os

def check(a, b):
    if a != b:
        print (a, b)

def cert(cn):
    return {'subject': ((('commonName', cn),),)}

from mercurial.sslutil import _verifycert

# Test non-wildcard certificates
check(_verifycert(cert('example.com'), 'example.com'),
      None)
check(_verifycert(cert('example.com'), 'www.example.com'),
      'certificate is for example.com')
check(_verifycert(cert('www.example.com'), 'example.com'),
      'certificate is for www.example.com')

# Test wildcard certificates
check(_verifycert(cert('*.example.com'), 'www.example.com'),
      None)
check(_verifycert(cert('*.example.com'), 'example.com'),
      'certificate is for *.example.com')
check(_verifycert(cert('*.example.com'), 'w.w.example.com'),
      'certificate is for *.example.com')

# Test subjectAltName
san_cert = {'subject': ((('commonName', 'example.com'),),),
            'subjectAltName': (('DNS', '*.example.net'),
                               ('DNS', 'example.net'))}
check(_verifycert(san_cert, 'example.net'),
      None)
check(_verifycert(san_cert, 'foo.example.net'),
      None)
# no fallback to subject commonName when subjectAltName has DNS
check(_verifycert(san_cert, 'example.com'),
      'certificate is for *.example.net, example.net')
# fallback to subject commonName when no DNS in subjectAltName
san_cert = {'subject': ((('commonName', 'example.com'),),),
            'subjectAltName': (('IP Address', '8.8.8.8'),)}
check(_verifycert(san_cert, 'example.com'), None)

# Avoid some pitfalls
check(_verifycert(cert('*.foo'), 'foo'),
      'certificate is for *.foo')
check(_verifycert(cert('*o'), 'foo'),
      'certificate is for *o')

check(_verifycert({'subject': ()},
                  'example.com'),
      'no commonName or subjectAltName found in certificate')
check(_verifycert(None, 'example.com'),
      'no certificate received')

# Unicode (IDN) certname isn't supported
check(_verifycert(cert(u'\u4f8b.jp'), 'example.jp'),
      'IDN in certificate not supported')

import doctest

def test_url():
    """
    >>> from mercurial.util import url

    This tests for edge cases in url.URL's parsing algorithm. Most of
    these aren't useful for documentation purposes, so they aren't
    part of the class's doc tests.

    Query strings and fragments:

    >>> url('http://host/a?b#c')
    <url scheme: 'http', host: 'host', path: 'a', query: 'b', fragment: 'c'>
    >>> url('http://host/a?')
    <url scheme: 'http', host: 'host', path: 'a'>
    >>> url('http://host/a#b#c')
    <url scheme: 'http', host: 'host', path: 'a', fragment: 'b#c'>
    >>> url('http://host/a#b?c')
    <url scheme: 'http', host: 'host', path: 'a', fragment: 'b?c'>
    >>> url('http://host/?a#b')
    <url scheme: 'http', host: 'host', path: '', query: 'a', fragment: 'b'>
    >>> url('http://host/?a#b', parsequery=False)
    <url scheme: 'http', host: 'host', path: '?a', fragment: 'b'>
    >>> url('http://host/?a#b', parsefragment=False)
    <url scheme: 'http', host: 'host', path: '', query: 'a#b'>
    >>> url('http://host/?a#b', parsequery=False, parsefragment=False)
    <url scheme: 'http', host: 'host', path: '?a#b'>

    IPv6 addresses:

    >>> url('ldap://[2001:db8::7]/c=GB?objectClass?one')
    <url scheme: 'ldap', host: '[2001:db8::7]', path: 'c=GB',
         query: 'objectClass?one'>
    >>> url('ldap://joe:xxx@[2001:db8::7]:80/c=GB?objectClass?one')
    <url scheme: 'ldap', user: 'joe', passwd: 'xxx', host: '[2001:db8::7]',
         port: '80', path: 'c=GB', query: 'objectClass?one'>

    Missing scheme, host, etc.:

    >>> url('://192.0.2.16:80/')
    <url path: '://192.0.2.16:80/'>
    >>> url('http://mercurial.selenic.com')
    <url scheme: 'http', host: 'mercurial.selenic.com'>
    >>> url('/foo')
    <url path: '/foo'>
    >>> url('bundle:/foo')
    <url scheme: 'bundle', path: '/foo'>
    >>> url('a?b#c')
    <url path: 'a?b', fragment: 'c'>
    >>> url('http://x.com?arg=/foo')
    <url scheme: 'http', host: 'x.com', query: 'arg=/foo'>
    >>> url('http://joe:xxx@/foo')
    <url scheme: 'http', user: 'joe', passwd: 'xxx', path: 'foo'>

    Just a scheme and a path:

    >>> url('mailto:[e-mail]')
    <url scheme: 'mailto', path: '[e-mail]'>
    >>> url('a:b:c:d')
    <url path: 'a:b:c:d'>
    >>> url('aa:bb:cc:dd')
    <url scheme: 'aa', path: 'bb:cc:dd'>

    SSH examples:

    >>> url('ssh://joe@host//home/joe')
    <url scheme: 'ssh', user: 'joe', host: 'host', path: '/home/joe'>
    >>> url('ssh://joe:xxx@host/src')
    <url scheme: 'ssh', user: 'joe', passwd: 'xxx', host: 'host', path: 'src'>
    >>> url('ssh://joe:xxx@host')
    <url scheme: 'ssh', user: 'joe', passwd: 'xxx', host: 'host'>
    >>> url('ssh://joe@host')
    <url scheme: 'ssh', user: 'joe', host: 'host'>
    >>> url('ssh://host')
    <url scheme: 'ssh', host: 'host'>
    >>> url('ssh://')
    <url scheme: 'ssh'>
    >>> url('ssh:')
    <url scheme: 'ssh'>

    Non-numeric port:

    >>> url('http://example.com:dd')
    <url scheme: 'http', host: 'example.com', port: 'dd'>
    >>> url('ssh://joe:xxx@host:ssh/foo')
    <url scheme: 'ssh', user: 'joe', passwd: 'xxx', host: 'host', port: 'ssh',
         path: 'foo'>

    Bad authentication credentials:

    >>> url('http://joe@joeville:123@4:@host/a?b#c')
    <url scheme: 'http', user: 'joe@joeville', passwd: '123@4:',
         host: 'host', path: 'a', query: 'b', fragment: 'c'>
    >>> url('http://!*#?/@!*#?/:@host/a?b#c')
    <url scheme: 'http', host: '!*', fragment: '?/@!*#?/:@host/a?b#c'>
    >>> url('http://!*#?@!*#?:@host/a?b#c')
    <url scheme: 'http', host: '!*', fragment: '?@!*#?:@host/a?b#c'>
    >>> url('http://!*@:!*@@host/a?b#c')
    <url scheme: 'http', user: '!*@', passwd: '!*@', host: 'host',
         path: 'a', query: 'b', fragment: 'c'>

    File paths:

    >>> url('a/b/c/d.g.f')
    <url path: 'a/b/c/d.g.f'>
    >>> url('/x///z/y/')
    <url path: '/x///z/y/'>
    >>> url('/foo:bar')
    <url path: '/foo:bar'>
    >>> url('\\\\foo:bar')
    <url path: '\\\\foo:bar'>
    >>> url('./foo:bar')
    <url path: './foo:bar'>

    Non-localhost file URL:

    >>> u = url('file://mercurial.selenic.com/foo')
    Traceback (most recent call last):
      File "<stdin>", line 1, in ?
    Abort: file:// URLs can only refer to localhost

    Empty URL:

    >>> u = url('')
    >>> u
    <url path: ''>
    >>> str(u)
    ''

    Empty path with query string:

    >>> str(url('http://foo/?bar'))
    'http://foo/?bar'

    Invalid path:

    >>> u = url('http://foo/bar')
    >>> u.path = 'bar'
    >>> str(u)
    'http://foo/bar'

    >>> u = url('file:/foo/bar/baz')
    >>> u
    <url scheme: 'file', path: '/foo/bar/baz'>
    >>> str(u)
    'file:///foo/bar/baz'
    >>> u.localpath()
    '/foo/bar/baz'

    >>> u = url('file:///foo/bar/baz')
    >>> u
    <url scheme: 'file', path: '/foo/bar/baz'>
    >>> str(u)
    'file:///foo/bar/baz'
    >>> u.localpath()
    '/foo/bar/baz'

    >>> u = url('file:///f:oo/bar/baz')
    >>> u
    <url scheme: 'file', path: 'f:oo/bar/baz'>
    >>> str(u)
    'file:///f:oo/bar/baz'
    >>> u.localpath()
    'f:oo/bar/baz'

    >>> u = url('file://localhost/f:oo/bar/baz')
    >>> u
    <url scheme: 'file', host: 'localhost', path: 'f:oo/bar/baz'>
    >>> str(u)
    'file://localhost/f:oo/bar/baz'
    >>> u.localpath()
    'f:oo/bar/baz'

    >>> u = url('file:foo/bar/baz')
    >>> u
    <url scheme: 'file', path: 'foo/bar/baz'>
    >>> str(u)
    'file:foo/bar/baz'
    >>> u.localpath()
    'foo/bar/baz'
    """

if 'TERM' in os.environ:
    del os.environ['TERM']

doctest.testmod(optionflags=doctest.NORMALIZE_WHITESPACE)