[Python-Dev] [Python-checkins] cpython (3.3): - Issue #16514: Fix regression causing a traceback when sys.path[0] is None
Brett Cannon
brett at python.org
Tue Nov 20 23:12:28 CET 2012
Should you also insert None into sys.path_importer_cache to signify there
is no finder for the path entry? I guess the real problem with that is
there is no guarantee the path entry is hashable, so that probably won't
work. So nevermind. =)
On Tue, Nov 20, 2012 at 3:35 PM, barry.warsaw <python-checkins at python.org>wrote:
> http://hg.python.org/cpython/rev/291406748217
> changeset: 80529:291406748217
> branch: 3.3
> parent: 80527:4537dd27b2dc
> user: Barry Warsaw <barry at python.org>
> date: Tue Nov 20 15:22:51 2012 -0500
> summary:
> - Issue #16514: Fix regression causing a traceback when sys.path[0] is
> None
> (actually, any non-string or non-bytes type).
>
> files:
> Doc/library/sys.rst | 4 +-
> Doc/reference/import.rst | 24 +-
> Lib/importlib/_bootstrap.py | 2 +
> Lib/test/test_importlib/import_/test_path.py | 25 +-
> Misc/NEWS | 3 +
> Python/importlib.h | 130 +++++----
> 6 files changed, 111 insertions(+), 77 deletions(-)
>
>
> diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
> --- a/Doc/library/sys.rst
> +++ b/Doc/library/sys.rst
> @@ -783,7 +783,9 @@
> current directory first. Notice that the script directory is inserted
> *before*
> the entries inserted as a result of :envvar:`PYTHONPATH`.
>
> - A program is free to modify this list for its own purposes.
> + A program is free to modify this list for its own purposes. Only
> strings
> + and bytes should be added to :data:`sys.path`; all other data types are
> + ignored during import.
>
>
> .. seealso::
> diff --git a/Doc/reference/import.rst b/Doc/reference/import.rst
> --- a/Doc/reference/import.rst
> +++ b/Doc/reference/import.rst
> @@ -540,7 +540,10 @@
> implementation-specific defaults. Entries in :data:`sys.path` can name
> directories on the file system, zip files, and potentially other
> "locations"
> (see the :mod:`site` module) that should be searched for modules, such as
> -URLs, or database queries.
> +URLs, or database queries. Only strings and bytes should be present on
> +:data:`sys.path`; all other data types are ignored. The encoding of bytes
> +entries is determined by the individual :term:`path entry finders <path
> entry
> +finder>`.
>
> The :term:`path based finder` is a :term:`meta path finder`, so the import
> machinery begins the :term:`import path` search by calling the path
> @@ -563,14 +566,17 @@
> the path based finder to perform the path entry search again [#fnpic]_.
>
> If the path entry is not present in the cache, the path based finder
> iterates
> -over every callable in :data:`sys.path_hooks`. Each of the
> -:term:`path entry hooks <path entry hook>` in this list is called with a
> -single argument, the path entry to be searched. This callable may either
> -return a :term:`path entry finder` that can handle the path entry, or it
> may
> -raise :exc:`ImportError`.
> -An :exc:`ImportError` is used by the path based finder to signal that the
> hook
> -cannot find a :term:`path entry finder` for that :term:`path entry`. The
> -exception is ignored and :term:`import path` iteration continues.
> +over every callable in :data:`sys.path_hooks`. Each of the :term:`path
> entry
> +hooks <path entry hook>` in this list is called with a single argument,
> the
> +path entry to be searched. This callable may either return a :term:`path
> +entry finder` that can handle the path entry, or it may raise
> +:exc:`ImportError`. An :exc:`ImportError` is used by the path based
> finder to
> +signal that the hook cannot find a :term:`path entry finder` for that
> +:term:`path entry`. The exception is ignored and :term:`import path`
> +iteration continues. The hook should expect either a string or bytes
> object;
> +the encoding of bytes objects is up to the hook (e.g. it may be a file
> system
> +encoding, UTF-8, or something else), and if the hook cannot decode the
> +argument, it should raise :exc:`ImportError`.
>
> If :data:`sys.path_hooks` iteration ends with no :term:`path entry finder`
> being returned, then the path based finder's :meth:`find_module()` method
> diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py
> --- a/Lib/importlib/_bootstrap.py
> +++ b/Lib/importlib/_bootstrap.py
> @@ -1281,6 +1281,8 @@
> # the list of paths that will become its __path__
> namespace_path = []
> for entry in path:
> + if not isinstance(entry, (str, bytes)):
> + continue
> finder = cls._path_importer_cache(entry)
> if finder is not None:
> if hasattr(finder, 'find_loader'):
> diff --git a/Lib/test/test_importlib/import_/test_path.py
> b/Lib/test/test_importlib/import_/test_path.py
> --- a/Lib/test/test_importlib/import_/test_path.py
> +++ b/Lib/test/test_importlib/import_/test_path.py
> @@ -1,15 +1,14 @@
> from importlib import _bootstrap
> from importlib import machinery
> +from importlib import import_module
> from .. import util
> from . import util as import_util
> -import imp
> import os
> import sys
> -import tempfile
> -from test import support
> -from types import MethodType
> +from types import ModuleType
> import unittest
> import warnings
> +import zipimport
>
>
> class FinderTests(unittest.TestCase):
> @@ -89,6 +88,24 @@
> self.assertIs(loader, importer)
> self.assertIn(os.curdir, sys.path_importer_cache)
>
> + def test_None_on_sys_path(self):
> + # Putting None in sys.path[0] caused an import regression from
> Python
> + # 3.2: http://bugs.python.org/issue16514
> + new_path = sys.path[:]
> + new_path.insert(0, None)
> + new_path_importer_cache = sys.path_importer_cache.copy()
> + new_path_importer_cache.pop(None, None)
> + new_path_hooks = [zipimport.zipimporter,
> + _bootstrap.FileFinder.path_hook(
> + *_bootstrap._get_supported_file_loaders())]
> + with util.uncache('email'):
> + with util.import_state(meta_path=sys.meta_path[:],
> + path=new_path,
> +
> path_importer_cache=new_path_importer_cache,
> + path_hooks=new_path_hooks):
> + module = import_module('email')
> + self.assertIsInstance(module, ModuleType)
> +
>
> def test_main():
> from test.support import run_unittest
> diff --git a/Misc/NEWS b/Misc/NEWS
> --- a/Misc/NEWS
> +++ b/Misc/NEWS
> @@ -12,6 +12,9 @@
> Core and Builtins
> -----------------
>
> +- Issue #16514: Fix regression causing a traceback when sys.path[0] is
> None
> + (actually, any non-string or non-bytes type).
> +
> - Issue #16306: Fix multiple error messages when unknown command line
> parameters where passed to the interpreter. Patch by Hieu Nguyen.
>
> diff --git a/Python/importlib.h b/Python/importlib.h
> --- a/Python/importlib.h
> +++ b/Python/importlib.h
> [stripped]
>
> --
> Repository URL: http://hg.python.org/cpython
>
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>
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