"Jeff L" lats@yless4u.com.au wrote:
Looking a bit further it seems that NtCreateMailslotFile is only called from CreateMailslotW. If there is a problem with a NULL then it stems from there. http://source.winehq.org/ident?i=CreateMailslotW
NtCreateMailslotFile is a public API, so probably it should handle the case when attr is NULL. I see the same problem at least in NtCreateNamedPipeFile. In general, handling of OBJECT_ATTRIBUTES in ntdll is not consistent, but fixing it properly most likely a test is needed to see what Windows does in that case.