ntdll: Fix returned error for NtCreateKey with empty name.

dlls/ntdll/tests/reg.c

@@ -603,7 +603,6 @@ static void test_NtCreateKey(void)
 
     pRtlCreateUnicodeStringFromAsciiz( &str, "" );
     status = pNtCreateKey( &subkey, am, &attr, 0, 0, 0, 0 );
-    todo_wine
     ok( status == STATUS_OBJECT_PATH_SYNTAX_BAD, "NtCreateKey failed: 0x%08lx\n", status );
     pRtlFreeUnicodeString( &str );
 

dlls/ntdll/unix/registry.c

@@ -81,6 +81,7 @@ NTSTATUS WINAPI NtCreateKey( HANDLE *key, ACCESS_MASK access, const OBJECT_ATTRI
 
     *key = 0;
     if (attr->Length != sizeof(OBJECT_ATTRIBUTES)) return STATUS_INVALID_PARAMETER;
+    if (!attr->ObjectName->Length && !attr->RootDirectory) return STATUS_OBJECT_PATH_SYNTAX_BAD;
     if ((ret = alloc_object_attributes( attr, &objattr, &len ))) return ret;
 
     TRACE( "(%p,%s,%s,%x,%x,%p)\n", attr->RootDirectory, debugstr_us(attr->ObjectName),