GetFullPathName returns length without nul byte

reactos/lib/setupapi

diff -u -r1.3 -r1.4
--- parser.c	20 Mar 2004 21:55:24 -0000	1.3
+++ parser.c	6 Oct 2004 23:46:09 -0000	1.4
@@ -1063,6 +1063,7 @@

     if (strchrW( name, '\\' ) || strchrW( name, '/' ))
     {
         if (!(len = GetFullPathNameW( name, 0, NULL, NULL ))) return (HINF)INVALID_HANDLE_VALUE;

+        len++; /* Make room for terminating NUL byte */

         if (!(path = HeapAlloc( GetProcessHeap(), 0, len * sizeof(WCHAR) )))
         {
             SetLastError( ERROR_NOT_ENOUGH_MEMORY );