Full_Name: Dror Harari
Version:
OS: Windows 7 64bit
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (79.181.198.22)
The default compare functions start with:
mdb_cmp_memn(const MDB_val *a, const MDB_val *b)
{
int diff;
ssize_t len_diff;
unsigned int len;
len = a->mv_size;
len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
if (len_diff > 0) {
This code assumes that ssize_t is signed and in all normal platforms it is.
However, on Windows Visal Studio 2010 (did not check others) it is defined as:
#ifndef _SSIZE_T_DEFINED
#ifdef _WIN64
typedef unsigned __int64 ssize_t;
#else
typedef _W64 unsigned int ssize_t;
#endif
#define _SSIZE_T_DEFINED
#endif
So it is unsigned and len_diff would never become <0.
There's a workaround to defined a custom compare function but one can rewrite
the default compare around this bug (that is, avoiding subtraction).
This issue was detected with SET_KEY_RANGE on a key value of 00 00 00 02 where
the database had keys:
00 00 00 01 65
00 00 00 02 65
00 00 00 03 65
Instead of getting the 00 00 00 02 65, the code returns 00 00 00 03 65
