Proposal: fix assertion 'check_bin'

I'm not quite sure. 
What I have seen is that some numbers like 128 was wrong.
For example: 128 ( 10000000 ) replace it with 00000001
But I do not understand exactly what you are trying here.
Sorry - commented in your repo by accident.

I brought this over into my codebase and it triggered the assert. Did the original *not* trigger the assert for you?