kernelbase: Set ERROR_ALREADY_EXISTS for existing pipe in CreateNamedPipeW().

dlls/kernelbase/sync.c

@@ -1305,12 +1305,12 @@ HANDLE WINAPI DECLSPEC_HOTPATCH CreateNamedPipeW( LPCWSTR name, DWORD open_mode,
     if (instances >= PIPE_UNLIMITED_INSTANCES) instances = ~0U;
 
     time.QuadPart = (ULONGLONG)timeout * -10000;
-    SetLastError( 0 );
     status = NtCreateNamedPipeFile( &handle, access, &attr, &iosb, sharing,
                                     FILE_OPEN_IF, options, pipe_type,
                                     read_mode, non_block, instances, in_buff, out_buff, &time );
     RtlFreeUnicodeString( &nt_name );
     if (!set_ntstatus( status )) return INVALID_HANDLE_VALUE;
+    SetLastError( iosb.Information == FILE_CREATED ? ERROR_SUCCESS : ERROR_ALREADY_EXISTS );
     return handle;
 }
 

dlls/ntdll/tests/om.c

@@ -411,7 +411,6 @@ static void test_name_collisions(void)
     h1 = CreateNamedPipeA( "\\\\.\\pipe\\named_pipe", PIPE_ACCESS_DUPLEX,
                           PIPE_READMODE_BYTE, 10, 256, 256, 1000, NULL );
     winerr = GetLastError();
-    todo_wine
     ok(h1 != 0 && winerr == ERROR_ALREADY_EXISTS, "CreateNamedPipeA got ret=%p (%ld)\n", h1, winerr);
     pNtClose(h1);
     pNtClose(h);