Function qpencode

engine/script/src/luasocket/mime.c:393–431

-------------------------------------------------------------------------*\ * Accumulate characters until we are sure about how to deal with them. * Once we are sure, output to the buffer, in the correct form. \*-------------------------------------------------------------------------*/

* Once we are sure, output to the buffer, in the correct form. 
\*-------------------------------------------------------------------------*/
static size_t qpencode(UC c, UC *input, size_t size, 
        const char *marker, luaL_Buffer *buffer)
{
    input[size++] = c;
    /* deal with all characters we can have */
    while (size > 0) {
        switch (qpclass[input[0]]) {
            /* might be the CR of a CRLF sequence */
            case QP_CR:
                if (size < 2) return size;
                if (input[1] == '\n') {
                    luaL_addstring(buffer, marker);
                    return 0;
                } else qpquote(input[0], buffer);
                break;
            /* might be a space and that has to be quoted if last in line */
            case QP_IF_LAST:
                if (size < 3) return size;
                /* if it is the last, quote it and we are done */
                if (input[1] == '\r' && input[2] == '\n') {
                    qpquote(input[0], buffer);
                    luaL_addstring(buffer, marker);
                    return 0;
                } else luaL_addchar(buffer, input[0]);
                break;
                /* might have to be quoted always */
            case QP_QUOTED:
                qpquote(input[0], buffer);
                break;
                /* might never have to be quoted */
            default:
                luaL_addchar(buffer, input[0]);
                break;
        }
        input[0] = input[1]; input[1] = input[2];
        size--;
    }
    return 0;
}

/*-------------------------------------------------------------------------*\
* Deal with the final characters