[PATCH] git-p4: import the ctypes module

From: Dennis Kaarsemaker <dennis@kaarsemaker.net>
Date: Oct 20, 2015, 19:31 UTC
Message-ID: <1445369506.8543.10.camel@kaarsemaker.net>
In-Reply-To: <xmqqy4ex8r8k.fsf@gitster.mtv.corp.google.com>

The ctypes module is used on windows to calculate free disk space, so it must be imported.

Signed-off-by: Dennis Kaarsemaker <dennis@kaarsemaker.net>
---
 git-p4.py | 1 +
 1 file changed, 1 insertion(+)

On di, 2015-10-20 at 09:00 -0700, Junio C Hamano wrote:

Show 32 quoted lines

> Luke Diamand <luke@diamand.org> writes:
> 
> > On 20 October 2015 at 11:34, Etienne Girard <
> > etienne.g.girard@gmail.com> wrote:
> > > Hello,
> > > 
> > > Git-p4 fail when I try to rebase with the error: "NameError:
> > > global
> > > name 'ctypes' is not defined". The error occurs when I use python
> > > 2.7.2 that is installed by default on my company's computers (it
> > > goes
> > > without saying that everything works fine with python 2.7.10).
> > > 
> > > I'm a beginner in python, but simply importing ctypes at the
> > > beginning
> > > of the script does the trick. I was wondering if submitting a
> > > patch
> > > for this issue is worth the trouble, when a satisfying solution
> > > is not
> > > using a 4 years old version of python.
> > 
> > If you're able to submit a patch that would be great!
> 
> Lars's  (git-p4: check free space during streaming,
> 2015-09-26) introduced two references to ctypes.* and there is no
> 'import ctypes' anywhere in the script.
> 
> I do not follow Python development, but does the above mean that
> with recent 2.x you can say ctypes without first saying "import
> ctypes"?  It feels somewhat non-pythonesque that identifiers like
> this is given to you without you asking with an explicit 'import',
> so I am puzzled.

No, you cannot do that. The reason others may not have noticed this bug is that in git-p4.py, ctypes is only used on windows.

 111     if platform.system() == 'Windows':
 112         free_bytes = ctypes.c_ulonglong(0)
 113         ctypes.windll.kernel32.GetDiskFreeSpaceExW(ctypes.c_wchar_p(os.getcwd()), None, None, ctypes.pointer(free_bytes))

The fact that it works for the OP with 2.7.10 is puzzling (assuming that it's on the same system). But this patch should help.

diff --git a/git-p4.py b/git-p4.py
index daa60c6..212ef2b 100755
--- a/git-p4.py
+++ b/git-p4.py
@@ -24,6 +24,7 @@ import shutil
 import stat
 import zipfile
 import zlib
+import ctypes
 
 try:
     from subprocess import CalledProcessError

-- 
2.6.2-323-g60bd420