Patch #753465 a fix for Bug#750363.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@21082 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

contrib/src/gizmos/splittree.cpp

@@ -311,7 +311,7 @@ void wxRemotelyScrolledTreeCtrl::AdjustRemoteScrollbars()
         if (scrolledWindow)
         {
             wxRect itemRect;
-            if (GetBoundingRect(GetRootItem(), itemRect))
+            if (GetBoundingRect(GetFirstVisibleItem(), itemRect))
             {
                 // Actually, the real height seems to be 1 less than reported
                 // (e.g. 16 instead of 16)

src/msw/treectrl.cpp

@@ -1921,6 +1921,13 @@ bool wxTreeCtrl::GetBoundingRect(const wxTreeItemId& item,
                                  bool textOnly) const
 {
     RECT rc;
+
+    // Virtual root items have no bounding rectangle
+    if ( IS_VIRTUAL_ROOT(item) )
+    {
+        return false;
+    }
+
     if ( TreeView_GetItemRect(GetHwnd(), HITEM(item),
                               &rc, textOnly) )
     {