Commit most parts of #10495 wxDataViewCtrl needs a way to start the label editor programmatically

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@59438 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/datavcmn.cpp

@@ -702,6 +702,10 @@ bool wxDataViewRendererBase::StartEditing( const wxDataViewItem &item, wxRect la
 
     m_editorCtrl->PushEventHandler( handler );
 
+    // there might be no editor control for the given item
+    if (!m_editorCtrl)
+        return false;
+        
 #if defined(__WXGTK20__) && !defined(wxUSE_GENERICDATAVIEWCTRL)
     handler->SetFocusOnIdle();
 #else