No, I don't buy that this is intentional behavior. The function clearly expects a string of hex digits, and is prepending a zero only to avoid problems when the string is not well formed (odd length). The caller for whatever reason thinks the string can or should begin with a #. The caller clearly thinks it's passing a well formed 3 byte string. The function however thinks this is not well formed and sticks a zero in front of the # producing the bizarre FOUR byte string 0#F6F6F6 that neither the caller nor the callee would call well formed. If the caller passed "#12345678", the function would be parsing the FIVE(!) byte string "0#12345678". IMHO rejoicing in the fact that the code nevertheless works is not the best response to this mess.
--Mark