This fixes a bug where some verions of mingw and probably gcc
assume that the result of pointer subtraction will be non-NULL,
causing MSI_OpenDatabaseW to break when given the mode
MSIDBOPEN_READONLY + MSIDBOPEN_PATCHFILE.
Signed-off-by: Vincent Povirk <vincent@codeweavers.com>
Signed-off-by: Hans Leidekker <hans@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>