Segmentation Fault after get_default_device (restype: int, pointer: long) about python-discid HOT 3 CLOSED

The underlying problem is that the default for restype is c_int and pointers have a c_long similar length, on 64 bit Linux.

A quick fix is to set the restype to c_long and leave everything else or use prototypes in general.

When we use prototypes, we might set them all in one place, which separates them from the corresponding python function.s

Creating a MyCDLL with _func_restype_ = c_long might be another possibility.

Altogether this could mean a bigger change in design so I just commited this as-is now.

from python-discid.

I added a test for this in 934d05d9d34a0109031a99f0f9699074c34f7efa (branch restype_long)

./discid.py in that test version gives on 64 bit Linux, Python 3.2.3 (same on Python 2.7.3, but with ()):

<class 'int'>
default: 610197754
<class 'int'>
c_int: 610197754
<class 'int'>
c_long: 140175457837306
<class 'int'>
c_void_p: 140175457837306

c_char_p(140175457837306)
/dev/cdrom

On 32 bit Windows XP (in a virtual machine, Python 2.7.3):

<type 'int'>
default: 1765843380
<type 'int'>
c_int: 1765843380
<type 'int'>
c_long: 1765843380
<type 'int'>
c_void_p: 1765843380
()
c_char_p('cdaudio')
cdaudio

On Cygwin (on the same Windows in the same virtual machine, Python 2.6.8):

<type 'int'>
default: 1693471444
<type 'int'>
c_int: 1693471444
<type 'int'>
c_long: 1693471444
<type 'int'>
c_void_p: 1693471444
()
c_char_p(1693471444)
cdaudio

from python-discid.

On python there is no distinction made. See also PEP-0237.

from python-discid.