user32: Use IDOK as default identifier in a template.

dlls/user32/dialog.c

@@ -674,7 +674,7 @@ static HWND DIALOG_CreateIndirect( HINSTANCE hInst, LPCVOID dlgTemplate,
     dlgInfo->hMenu       = hMenu;
     dlgInfo->xBaseUnit   = xBaseUnit;
     dlgInfo->yBaseUnit   = yBaseUnit;
-    dlgInfo->idResult    = 0;
+    dlgInfo->idResult    = IDOK;
     dlgInfo->flags       = flags;
     dlgInfo->hDialogHeap = 0;
 

dlls/user32/tests/dialog.c

@@ -930,6 +930,19 @@ static INT_PTR CALLBACK DestroyOnCloseDlgWinProc (HWND hDlg, UINT uiMsg,
     return FALSE;
 }
 
+
+static INT_PTR CALLBACK TestDefButtonDlgProc (HWND hDlg, UINT uiMsg,
+                                              WPARAM wParam, LPARAM lParam)
+{
+    switch (uiMsg)
+    {
+    case WM_INITDIALOG:
+        EndDialog(hDlg, LOWORD(SendMessage(hDlg, DM_GETDEFID, 0, 0)));
+        return TRUE;
+    }
+    return FALSE;
+}
+
 static void test_DialogBoxParamA(void)
 {
     INT_PTR ret;
@@ -968,6 +981,9 @@ static void test_DialogBoxParamA(void)
     ok(GetLastError() == ERROR_INVALID_WINDOW_HANDLE ||
        broken(GetLastError() == 0xdeadbeef),
        "got %d, expected ERROR_INVALID_WINDOW_HANDLE\n", GetLastError());
+
+    ret = DialogBoxParamA(GetModuleHandle(NULL), "TEST_EMPTY_DIALOG", 0, TestDefButtonDlgProc, 0);
+    ok(ret == IDOK, "Expected IDOK\n");
 }
 
 static void test_DisabledDialogTest(void)

dlls/user32/tests/resource.rc

@@ -98,6 +98,13 @@ BEGIN
     PUSHBUTTON      "Cancel",IDCANCEL,129,24,50,14
 END
 
+TEST_EMPTY_DIALOG DIALOG DISCARDABLE  0, 0, 186, 95
+STYLE DS_MODALFRAME | WS_POPUP | WS_CAPTION | WS_SYSMENU
+CAPTION "Dialog"
+FONT 8, "MS Sans Serif"
+BEGIN
+END
+
 MULTI_EDIT_DIALOG DIALOG DISCARDABLE 0, 0, 160, 75
 STYLE WS_POPUP | WS_CAPTION | WS_SYSMENU | WS_MINIMIZEBOX | DS_CENTER
 CAPTION "Multiple Edit Test"