[ctypes-commit] ctypes/source _ctypes.c,1.326,1.327

[Thomas H. <th...@us...>]

Update of /cvsroot/ctypes/ctypes/source
In directory sc8-pr-cvs4.sourceforge.net:/tmp/cvs-serv8674

Modified Files:
	_ctypes.c 
Log Message:
Change the way unique_key calculates the keys into the b_objects
array.  The previous way was broken for arrays or structures having
more than 256 components, which led to strange errors.


Index: _ctypes.c
===================================================================
RCS file: /cvsroot/ctypes/ctypes/source/_ctypes.c,v
retrieving revision 1.326
retrieving revision 1.327
diff -C2 -d -r1.326 -r1.327
*** _ctypes.c	18 May 2006 09:45:53 -0000	1.326
--- _ctypes.c	19 May 2006 15:41:49 -0000	1.327
***************
*** 1814,1834 ****
  
  static PyObject *
! unique_key(CDataObject *target, int index)
  {
! 	char string[256]; /* XXX is that enough? */
  	char *cp = string;
! 	*cp++ = index + '0';
  	while (target->b_base) {
! 		*cp++ = target->b_index + '0';
  		target = target->b_base;
  	}
  	return PyString_FromStringAndSize(string, cp-string);
  }
! /* Keep a reference to 'keep' in the 'target', at index 'index' */
  /*
!  * KeepRef travels the target's b_base pointer down to the root,
!  * building a sequence of indexes during the path.  The indexes, which are a
!  * couple of small integers, are used to build a byte string usable as
!  * key int the root object's _objects dict.
   *
   * Note: This function steals a refcount of the third argument, even if it
--- 1814,1853 ----
  
  static PyObject *
! unique_key(CDataObject *target, Py_ssize_t index)
  {
! 	char string[256];
  	char *cp = string;
! 	size_t bytes_left;
! 
! 	assert(sizeof(string) - 1 > sizeof(Py_ssize_t) * 2);
! 	cp += sprintf(cp, "%x", index);
  	while (target->b_base) {
! 		bytes_left = sizeof(string) - (cp - string) - 1;
! 		/* Hex format needs 2 characters per byte */
! 		if (bytes_left < sizeof(Py_ssize_t) * 2) {
! 			PyErr_SetString(PyExc_ValueError,
! 					"ctypes object structure too deep");
! 			return NULL;
! 		}
! 		cp += sprintf(cp, ":%x", index);
  		target = target->b_base;
  	}
  	return PyString_FromStringAndSize(string, cp-string);
  }
! 
  /*
!  * Keep a reference to 'keep' in the 'target', at index 'index'.
!  *
!  * If 'keep' is None, do nothing.
!  *
!  * Otherwise create a dictionary (if it does not yet exist) id the root
!  * objects 'b_objects' item, which will store the 'keep' object under a unique
!  * key.
!  *
!  * The unique_key helper travels the target's b_base pointer down to the root,
!  * building a string containing hex-formatted indexes found during traversal,
!  * separated by colons.
!  *
!  * The index tuple is used as a key into the root object's b_objects dict.
   *
   * Note: This function steals a refcount of the third argument, even if it
***************
*** 1854,1857 ****
--- 1873,1880 ----
  	}
  	key = unique_key(target, index);
+ 	if (key == NULL) {
+ 		Py_DECREF(keep);
+ 		return -1;
+ 	}
  	result = PyDict_SetItem(ob->b_objects, key, keep);
  	Py_DECREF(key);