Tcl_Panic("%s called with shared object","TclAppendBytesToByteArray");
    }
    if (len == TCL_AUTO_LENGTH) {
	Tcl_Panic("%s must be called with definite number of bytes to append",
		"TclAppendBytesToByteArray");
    }
    if (len == 0) {
	/*
	 * Append zero bytes is a no-op.
	 */

	return;
    }

    irPtr = TclFetchIntRep(objPtr, &properByteArrayType);
    if (irPtr == NULL) {
	irPtr = TclFetchIntRep(objPtr, &tclByteArrayType);
	if (irPtr == NULL) {