+ /** Contructs a file name of a referenced file (child doc, included graphics etc).
+ * Absolute names are returned as is. If the name is relative, it is
+ * interpreted relative to filePath() if the file exists, otherwise
+ * relative to the original path where the document was last saved.
+ * The original path may be different from filePath() if the document was
+ * later manually moved to a different location.
+ */
+ support::DocFileName getReferencedFileName(std::string const & fn) const;
+