Fix: Decoding a udp buffer with an argument of type blob fails with nom error EOF.

[IRSMsoso]

I've noticed when using decoder::decode() on a udp packet with a blob argument it fails with a nom EOF error when the blob size is a multiple of 4. I tracked this to the pad_to_32_bit_boundary() of read_blob().

let offset = (4 - original_input.offset(input) % 4) % 4;
        let (input, _) = take(offset)(input)?;
        Ok((input, ()))

This parser seems to assume that if the blob is a multiple of 4, there will be 4 more zero bytes to take(), but from my experience this isn't the case. Giving it another modulo so that multiples of 4 take 0 additional bytes fixed my issue.

[IRSMsoso]

Nevermind, duplicate of #51, not sure how I didn't see that.

[klingtnet]

@IRSMsoso if you're still interested in the patch feel free to take a look at #51 (comment). I'm wondering why the tests break if I apply a simplified, but equivalent, version of your patch. It might be that there's some other bug lurking. Would appreciate any help.

[IRSMsoso]

Yeah I realized after I saw the other pull request that my solution fixed the issue with glob padding but broke other places that used that parser, which I assume is why it was broken up in the other PR. So I closed this one. But would love to see the other PR merged.