demandimport: do not raise ImportError for unknown item in fromlist
This is the behavior of the default __import__() function, which doesn't
validate the existence of the fromlist items. Later on, the missing attribute
is detected while processing the import statement.
https://hg.python.org/cpython/file/v2.7.13/Python/import.c#l2575
The comtypes library relies on this (maybe) undocumented behavior, and we
got a bug report to TortoiseHg, sigh.
https://bitbucket.org/tortoisehg/thg/issues/4647/
The test added at
26a4e46af2bc verifies the behavior of the import statement,
so this patch only adds the test of __import__() function and works around
CPython/PyPy difference.
from __future__ import absolute_import
import __builtin__
import os
from mercurial import (
util,
)
def lowerwrap(scope, funcname):
f = getattr(scope, funcname)
def wrap(fname, *args, **kwargs):
d, base = os.path.split(fname)
try:
files = os.listdir(d or '.')
except OSError:
files = []
if base in files:
return f(fname, *args, **kwargs)
for fn in files:
if fn.lower() == base.lower():
return f(os.path.join(d, fn), *args, **kwargs)
return f(fname, *args, **kwargs)
scope.__dict__[funcname] = wrap
def normcase(path):
return path.lower()
os.path.normcase = normcase
for f in 'file open'.split():
lowerwrap(__builtin__, f)
for f in "chmod chown open lstat stat remove unlink".split():
lowerwrap(os, f)
for f in "exists lexists".split():
lowerwrap(os.path, f)
lowerwrap(util, 'posixfile')