Check for null text control in wxPickerBase fixing a focus event crash on control deletion that will need to eventually be fixed, but this should be done anyway, and at least fixes wxFilePickerCtrl for now.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@58463 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/pickerbase.cpp

@@ -149,7 +149,7 @@ void wxPickerBase::OnTextCtrlKillFocus(wxFocusEvent& event)
     event.Skip();
 
     // don't leave the textctrl empty
-    if (m_text->GetValue().empty())
+    if (m_text && m_text->GetValue().empty())
         UpdateTextCtrlFromPicker();
 }