PadToMinSize may break AddOption

[remohammadi]

AddOption expects that the packet is ended with END, but if the initial packet was smaller than 300 bytes, PadToMinSize is called and so the packet is padded and AddOption doesn't remove the END.

Can we postpone PadToMinSize until Serve?

[krolaw]

That would be a breaking change for those who run their own Serve, as one can currently expect that the message packets coming out of New and Reply to be valid messages ready to go.

One solution may be for AddOption to check for padding, and if it's there:
trim padding
defer PadToMinSize()
continue rest of function.

My question is however, is this a real problem? It appears to be only padded if you are calling New or Reply, which both expect you to pass your desired options upfront. AddOption is more about building the packet, not editing it (no DeleteOption for example). Perhaps the real solution is to improve the function comments.

Thoughts?

[remohammadi]

Thank you. We were modifying the packet on some condition. We fixed it by doing the changes on the options and then creating the packet and returning it without touching the result of ReplyPacket.