id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
180	WindowsError: [Error 183] from foolscap.test.test_logging.Filter.test_basic on Windows	davidsarah	Brian Warner	"After fixing #179 by replacing all ""w"" file open modes in foolscap code with ""wb"", the following error in the same test (foolscap.test.test_logging.Filter.test_basic) is unmasked:
{{{
[ERROR]
Traceback (most recent call last):
  File ""C:\cygwin\home\David-Sarah\tahoe\trunk\support\Lib\site-packages\foolscap-0.6.1-py2.7.egg\fo
olscap\test\test_logging.py"", line 1887, in _check
    (out,err) = cli.run_flogtool(argv[1:], run_by_human=False)
  File ""C:\cygwin\home\David-Sarah\tahoe\trunk\support\Lib\site-packages\foolscap-0.6.1-py2.7.egg\fo
olscap\logging\cli.py"", line 103, in run_flogtool
    dispatch(command, so)
  File ""C:\cygwin\home\David-Sarah\tahoe\trunk\support\Lib\site-packages\foolscap-0.6.1-py2.7.egg\fo
olscap\logging\cli.py"", line 67, in dispatch
    f.run(options)
  File ""C:\cygwin\home\David-Sarah\tahoe\trunk\support\Lib\site-packages\foolscap-0.6.1-py2.7.egg\fo
olscap\logging\filter.py"", line 103, in run
    os.rename(newfilename, options.newfile)
exceptions.WindowsError: [Error 183] Cannot create a file when that file already exists

foolscap.test.test_logging.Filter.test_basic
}}}

This seems to be due to a difference in behaviour between {{{os.rename}}} on Windows and Unix. On Linux, the destination directory entry is clobbered:

{{{
Python 2.6.6 (r266:84292, Sep 15 2010, 16:22:56) 
[GCC 4.4.5] on linux2
Type ""help"", ""copyright"", ""credits"" or ""license"" for more information.
>>> import os
>>> open(""test"", ""wb"").close()
>>> open(""test2"", ""wb"").close()
>>> os.rename(""test"", ""test2"")
>>> open(""test2"", ""rb"")
<open file 'test2', mode 'rb' at 0x7fe56c033db0>
>>> open(""test"", ""rb"")
Traceback (most recent call last):
  File ""<stdin>"", line 1, in <module>
IOError: [Errno 2] No such file or directory: 'test'
}}}

but on Windows XP an exception is raised:
{{{
Python 2.7.1 (r271:86832, Nov 27 2010, 18:30:46) [MSC v.1500 32 bit (Intel)] on win32
Type ""help"", ""copyright"", ""credits"" or ""license"" for more information.
>>> import os
>>> open(""test"", ""wb"").close()
>>> open(""test2"", ""wb"").close()
>>> os.rename(""test"", ""test2"")
Traceback (most recent call last):
  File ""<stdin>"", line 1, in <module>
WindowsError: [Error 183] Cannot create a file when that file already exists
}}}

(The inconsistency is [http://docs.python.org/library/os.html#os.rename documented] and [http://mail.python.org/pipermail/python-bugs-list/2004-March/022400.html apparently intentional].)
"	defect	closed	major	0.6.2	logging	0.6.1	fixed	windows logging review-needed