Good day. IIRC bash used to allow numeric constants of the BASE#DIGITS form even if the DIGITS part was empty. IOW: not only "64#0", but "64#" too was accepted as a valid zero constant.
This no longer works in 5.2.15, probably better than former behavior, "64#" looked quite confusing. However, a somewhat similar situation with hex prefix, 0xDIGITS, still allows just "0x" as a valid zero constant. Not sure whether this should be considered a bug, and whether it's worth fixing - just letting you know.
