crypto/rand: Read should call io.ReadFull

[jaekwon]

http://golang.org/pkg/crypto/rand/

The example is supposedly for the Read function, but it's actually just a usage of
Reader.

Fix: Move existing example under rand.Reader, and create a new example for rand.Read

[robpike]

Comment 1:

Labels changed: added priority-soon, go1.2, documentation, removed priority-triage, go1.2maybe.

Status changed to Accepted.

[bradfitz]

Comment 2:

Creating an example for Read is hard because it's hard to use correctly or usefully,
since it may return less than len(b).  If anything, we should change it and document it
to return exactly len(b) bytes or an error.

[rsc]

Comment 3:

Read should call io.ReadFull.

[bradfitz]

Comment 4:

This issue was closed by revision c327e82.

Status changed to Fixed.