comctl32/listview: Handle NULL lParam in LVM_SETITEMSTATE.

dlls/comctl32/listview.c

@@ -10653,6 +10653,7 @@ LISTVIEW_WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
     return LISTVIEW_SetItemPosition(infoPtr, (INT)wParam, *((POINT*)lParam));
 
   case LVM_SETITEMSTATE:
+    if (lParam == 0) return FALSE;
     return LISTVIEW_SetItemState(infoPtr, (INT)wParam, (LPLVITEMW)lParam);
 
   case LVM_SETITEMTEXTA:

dlls/comctl32/tests/listview.c

@@ -1963,6 +1963,10 @@ static void test_multiselect(void)
     item_count = (int)SendMessage(hwnd, LVM_GETITEMCOUNT, 0, 0);
     expect(items,item_count);
 
+    /* try with NULL pointer */
+    r = SendMessageA(hwnd, LVM_SETITEMSTATE, 0, (LPARAM)NULL);
+    expect(FALSE, r);
+
     /* select all, check notifications */
     ListView_SetItemState(hwnd, -1, 0, LVIS_SELECTED);