int *coli, int *rowi);
-#define _xml(X) (CHAR_CAST (const xmlChar *, X))
+#define _xml(X) (CHAR_CAST (const xmlChar *, (X)))
-#define _xmlchar_to_int(X) (atoi(CHAR_CAST (const char *, X)))
+#define _xmlchar_to_int(X) ((X) ? atoi (CHAR_CAST (const char *, (X))) : -1)
enum spreadsheet_type
{