branches/zip: fix Mantis issue #74 Memory leak on Windows

The memory leak was due to wrong parameters passed into VirtualFree()
call. So, the call fails with Windows error 87. MEM_DECOMMIT can NOT be
used along with MEM_RELEASE. And if the parameter is MEM_RELEASE, the
size parameter must be 0. The function frees the entire region that is
reserved in the initial allocation call to VirtualAlloc.

This issue was introduced by r984.

Approved by:	Heikki (on IM)

os/os0proc.c

@@ -186,7 +186,9 @@ os_mem_free_large(
 	}
 #endif /* HAVE_LARGE_PAGES && UNIV_LINUX */
 #ifdef __WIN__
-	if (!VirtualFree(ptr, size, MEM_DECOMMIT | MEM_RELEASE)) {
+	/* When RELEASE memory, the size parameter must be 0.
+	Do not use MEM_RELEASE with MEM_DECOMMIT. */
+	if (!VirtualFree(ptr, 0, MEM_RELEASE)) {
 		fprintf(stderr, "InnoDB: VirtualFree(%p, %lu) failed;"
 			" Windows error %lu\n",
 			ptr, (ulong) size, (ulong) GetLastError());