Comment 6 for bug 39547

It always compare to the version 1.0 of the CoC:
1/ sign CoC 1.0
2/ go to signature page for CoC 1.0.1
3/ reupload the signature for CoC 1.0, it works

Lots of bugs here:
a/ does not check against the correct CoC.txt version
b/ permits uploading twice the exact same signature
c/ no way to distinguish signatures in the list of signatures: does not list what CoC.txt is signed by each signature nor a precise date (only day, I signed both on the same day...)