* (missing one to three characters of a full quartet
* that encodes 1 - 3 bytes). Also: non-padding
* variants can be in incomplete state, from which
* data may need to be flushed...
*/
int left = dec.endOfContent();
if (left < 0) { // incomplete, error
throw _constructTypeException("Incomplete base64 triplet at the end of decoded content", "");
} else if (left > 0) { // 1 or 2 more bytes of data, loop some more
continue main_loop;
}