dror.harari@gmail.com wrote:
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.
If this is true, then you've found a bug in MSVC. The extra S in "SSIZE_T" means "signed." This is part of the C standard, and even the Microsoft documentation agrees with the standard (for once).
http://msdn.microsoft.com/en-us/library/windows/desktop/aa383751%28v=vs.85%2...
You should file a bug report with Microsoft. Closing this ITS.
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