encoding/base64: seems to get confused by newlines

[rsc]

http://play.golang.org/p/GmsYyaq9HF
This still happens at tip, and I don't think it should.
tip claims to ignore newlines. 
Also input byte 677 is in the middle of a line.

[gopherbot]

Comment 1 by pkwarren:

I investigated this issue and found it was a problem with the decoder reading an
incomplete chunk of data if there is embedded whitespace.
I was able to fix this by wrapping the io.Reader in NewDecoder with a reader which
filters out whitespace. Does this sound like an ok approach? If so I'll create a review
request.

[gopherbot]

Comment 2 by pkwarren:

Created a changeset: https://golang.org/cl/7311069/

[davecheney]

Comment 3:

fixed issue description, marked as started

Status changed to Started.

[gopherbot]

Comment 4 by remigius.gieben:

https://tools.ietf.org/html/rfc4648#section-3.1 says something about line-feeds in
encoded data. I don't see this is an issue, i.e. the current decoder works as
advertised. However if the golang-team wants to do something about this, should spaces
also be skipped when decoding?

[gopherbot]

Comment 5 by remigius.gieben:

The Decode() function works correctly. It is the Read function that is at fault. It
calculates the amount of data to read "nn := len(p) / 3 * 4", but disregards any 
line-feeds it might see when doing the io.ReadAtLeast(). 
I'm not sure how to proceed, create a new reader that removed line-feeds (and other
cruft) from the input?

[robpike]

Comment 6:

An injected Reader that drops \r and \n seems the simplest approach to me.

[gopherbot]

Comment 7 by remigius.gieben:

uploaded: https://golang.org/cl/7679043

[rsc]

Comment 8:

This issue was closed by revision b4237b5.

Status changed to Fixed.