In 2.6rc2, when I try to open a file with a unicode filename with a tab
in it, Python crashes on Win2000 and WinXP.  Bytestrings raise an
IOError as expected.  I'm using the Windows ia32 binaries.

C:\>c:\python26\python
Python 2.6rc2 (r26rc2:66507, Sep 18 2008, 14:27:33) [MSC v.1500 32 bit
(Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> f = open('c:\temp\temp.txt')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
IOError: invalid filename: c:   emp     emp.txt or mode: r
>>> f = open(u'c:\temp\temp.txt')
[[Crash happens here.]]
C:\>

I also get crashes for other unprintables \a \b \f \n \r \v \x03 and so on.

I'm not getting this on 2.5.2 or 3.0rc1.

Confirmed here. This also happens on Windows when the mode is invalid:
    open(u"foobar", "rr")

Here is a patch, please review.

The problem does not affect py3k because open() is used in place of
fopen(), and the mode string is parsed differently.

I think it is somewhat surprising that the file name shows up at the end
in the traceback. Instead of getting

IOError: [Errno 22] invalid filename or mode 'w': '/dos/foo\n'

it might be better if it said

IOError: [Errno 22] invalid mode ('w') or filename: '/dos/foo\n'

Otherwise, the patch looks fine.

Applied patch in r66620, with the suggested change in the error message.

And, thanks a lot reporting this!

Cheers.  First bug I've found in 5 years of Python.  (Or, 5 years in and
I still keep forgetting to use raw strings for Windows paths.  :)