Some problem in unrelease NSMutableString

[mulle-nat]

mulle-markdown-compose  --protect -c README.md.scion
mulle-scion: /home/src/srcO/MulleFoundation/MulleFoundationBase/src/MulleObjCValueFoundation/NSMutableString.m:748: void mulleConvertStringsToUTF8(NSString **, unsigned int, struct mulle_buffer *): Assertion `actual == len' failed.
/home/src/srcM/mulle-bashfunctions/src/mulle-bashfunctions.sh: line 1105: 79995 Aborted                 (core dumped) "$@"
make: *** [/dev/fd/63:6: README.md] Error 134

The culprit is one of the two UTF8 routines:

      len    = [s mulleUTF8StringLength];
      p      = mulle_buffer_advance( buffer, len);
      actual = [s mulleGetUTF8Characters:p
                               maxLength:len];