Fixed problem trying to print from a preview, whereby wrong printer

class was used instead of Gnome printer class.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@36493 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/dcpsg.cpp

@@ -1973,9 +1973,9 @@ void wxPostScriptDC::DoGetTextExtent(const wxString& string,
         //     it just crashes
 #ifndef __WIN32__
         wxPostScriptPrintNativeData *data =
-            (wxPostScriptPrintNativeData *) m_printData.GetNativeData();
+            wxDynamicCast(m_printData.GetNativeData(), wxPostScriptPrintNativeData);
 
-        if (!data->GetFontMetricPath().empty())
+        if (data && !data->GetFontMetricPath().empty())
         {
             afmName = data->GetFontMetricPath();
             afmName << wxFILE_SEP_PATH << name;