Added configure option --with-dmalloc to use the dmalloc memory debugging library.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@559 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/fileconf.cpp

@@ -1314,6 +1314,9 @@ wxString FilterIn(const wxString& str)
 // quote the string before writing it to file
 wxString FilterOut(const wxString& str)
 {
+   if(str.IsEmpty())
+      return str;
+   
   wxString strResult;
   strResult.Alloc(str.Len());