Applied patch [ 818941 ] Initialize vars and clear wxImageList

Also small speedup in wxFileIconsTable


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@24737 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/listctrl.cpp

@@ -4595,6 +4595,8 @@ bool wxGenericListCtrl::Create(wxWindow *parent,
     m_mainWin = (wxListMainWindow*) NULL;
     m_headerWin = (wxListHeaderWindow*) NULL;
 
+    m_headerHeight = 0;
+
     if ( !(style & wxLC_MASK_TYPE) )
     {
         style = style | wxLC_LIST;