Fix installing extension from local file on Windows

[takluyver]

Someone on Windows will need to test that this works. Pinging @jstenar.

Closes gh-1479

[fperez]

Code looks clean to me, but indeed we need confirmation from @jstenar or someone else with a Windows testing setup. @jdmarch, do you guys test on Windows regularly?

Thanks for the work, @takluyver! Go ahead with the merge once someone confirms it's OK on windows.

[jdmarch]

At quick look, this PR does not seem to make any difference on WinXP.

IPtest -v IPython.core.tests.test_magic

Produces 3 errors (test_macro, ...multi-line macro..., and test_extension) and 1 failure (..string escapes) before or after this PR. Whether the test_extension error is a side-effect of the preceding errors I do not know.

Possibly several days before I can return to this.

[fperez]

Thanks for the report, @jdmarch!

[takluyver]

@jdmarch (or anyone who can test on Windows): can you stick the results of that test (i.e. tracebacks) on a pastebin somewhere? Thanks.

[jdmarch]

@takluyver https://gist.github.com/2470181

[takluyver]

Gah, stupid mistake. Thanks for testing, hopefully it's fixed now.

[jdmarch]

Closer but not quite there:

======================================================================
ERROR: IPython.core.tests.test_magic.test_extension
----------------------------------------------------------------------
Traceback (most recent call last):
  File "c:\Python27\lib\site-packages\nose\case.py", line 197, in runTest
    self.test(*self.arg)
  File "c:\Documents and Settings\JDM\ipython\IPython\core\tests\test_magic.py", line 430, in test_extension
    _ip.magic("install_ext %s" % url)
  File "c:\documents and settings\jdm\ipython\IPython\core\interactiveshell.py", line 2036, in magic
    result = fn(magic_args)
  File "c:\documents and settings\jdm\ipython\IPython\core\magic.py", line 3459, in magic_install_ext
    filename, headers = self.extension_manager.install_extension(args, opts.get('n'))
TypeError: 'NoneType' object is not iterable

[takluyver]

Thanks, that one I should have caught on my own machine. If you could test again, that would be great.

[jdmarch]

Yes, test_extension passes now on WinXP.

[takluyver]

Thanks, Jonathan. I'll merge this now.

[fperez]

Thanks guys for the rapid back and forth! Glad to see this in.