fixed crash when wxHtmlWindow's content is updated when making selection

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@32578 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/html/htmlwin.cpp

@@ -181,6 +181,7 @@ void wxHtmlWindow::Init()
 #endif // wxUSE_CLIPBOARD
     m_backBuffer = NULL;
     m_eraseBgInOnPaint = false;
+    m_tmpSelFromCell = NULL;
 }
 
 bool wxHtmlWindow::Create(wxWindow *parent, wxWindowID id,
@@ -271,6 +272,9 @@ bool wxHtmlWindow::SetPage(const wxString& source)
 
     wxDELETE(m_selection);
 
+    // we will soon delete all the cells, so clear pointers to them:
+    m_tmpSelFromCell = NULL;
+
     // pass HTML through registered processors:
     if (m_Processors || m_GlobalProcessors)
     {