Bugs item #466752, was opened at 2001-10-01 01:10
You can respond by visiting:
http://sourceforge.net/tracker/?func=detail&atid=105470&aid=466752&group_id=5470
Category: Python Interpreter Core
Group: None
>Status: Closed
>Resolution: Rejected
Priority: 5
Submitted By: Nobody/Anonymous (nobody)
>Assigned to: Guido van Rossum (gvanrossum)
>Summary: "deref" error in _PyBuffer_FromObject
Initial Comment:
The "deref" code in function _PyBuffer_FromObject, file
bufferobject.c is an error:
==============
/* if the base object is another buffer, then
"deref" it */
if ( PyBuffer_Check(base) )
base = ((PyBufferObject*)base)->b_base;
return _PyBuffer_FromMemory(base, (char *)p + offset,
size, readonly);
==============
It is possible, that "deref"'ed base is NULL.
In this case the new object will have no reference to
any base object.
Example (in C):
================
base_buffer=PyBuffer_New(100);
derived_buffer=PyBuffer_FromObject(base_buffer,0,50);
Py_DECREF(base_buffer);
================
And derived_buffer memory pointer points to nowhere.
I think, the right code in _PyBuffer_FromObject would
be:
==============
/* if the base object is another buffer, then
"deref" it */
if ( PyBuffer_Check(base) &&
(((PyBufferObject*)base)->b_base != NULL))
base = ((PyBufferObject*)base)->b_base;
return _PyBuffer_FromMemory(base, (char *)p + offset,
size, readonly);
==============
Victor Sologoubov
VSologoubov@ibs.ru
----------------------------------------------------------------------
>Comment By: Guido van Rossum (gvanrossum)
Date: 2001-10-01 06:22
Message:
Logged In: YES
user_id=6380
Your example C code is simply wrong.
This has been brought up before (is there an example on the
web somewhere that does this???).
Do not use the buffer API to allocate memory.
----------------------------------------------------------------------
You can respond by visiting:
http://sourceforge.net/tracker/?func=detail&atid=105470&aid=466752&group_id=5470
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4