added length to wx(Scoped)CharBuffer to improve handling of embedded NULs

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@59927 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/defs.h

@@ -596,6 +596,10 @@ typedef short int WXTYPE;
 /*  integer on success as failure indicator */
 #define wxNOT_FOUND       (-1)
 
+/* the default value for some length parameters meaning that the string is */
+/* NUL-terminated */
+#define wxNO_LEN ((size_t)-1)
+
 /*  ---------------------------------------------------------------------------- */
 /*  macros dealing with comparison operators */
 /*  ---------------------------------------------------------------------------- */