Check for a valid buffer on NTReadFile

[Uwe Bonnes]

       Changelog:
       wine/dlls/ntdll/file.c: NtReadFile()
       Reject a NULL buffer       

This lets wine/dll/kernel/test/file.c:1389 succeed...
-- 
Uwe Bonnes                bon at elektron.ikp.physik.tu-darmstadt.de

Institut fuer Kernphysik  Schlossgartenstrasse 9  64289 Darmstadt
--------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------
Index: wine/dlls/ntdll/file.c
===================================================================
RCS file: /home/wine/wine/dlls/ntdll/file.c,v
retrieving revision 1.92
diff -u -r1.92 file.c
--- wine/dlls/ntdll/file.c	20 Jun 2005 10:31:04 -0000	1.92
+++ wine/dlls/ntdll/file.c	2 Jul 2005 18:17:16 -0000
@@ -467,6 +467,7 @@
           hFile,hEvent,apc,apc_user,io_status,buffer,length,offset,key);
 
     if (!io_status) return STATUS_ACCESS_VIOLATION;
+    if (!buffer) return STATUS_ACCESS_VIOLATION;
 
     io_status->Information = 0;
     io_status->u.Status = wine_server_handle_to_fd( hFile, GENERIC_READ, &unix_handle, &flags );