unicode/utf16: redundant code in EncodeRune

[gopherbot]

by chanxuehong:

in the func EncodeRune, it seems the code "|| IsSurrogate(r)" can be removed,
yes?

func EncodeRune(r rune) (r1, r2 rune) {
    if r < surrSelf || r > maxRune || IsSurrogate(r) {
        return replacementChar, replacementChar
    }
    r -= surrSelf
    return surr1 + (r>>10)&0x3ff, surr2 + r&0x3ff
}

[minux]

Comment 1:

As dave suggested, please consider add separate test for IsSurrogate along with this
change.

Labels changed: added release-none, repo-main.

Status changed to Accepted.

[davecheney]

Comment 2:

This issue was updated by revision fb31a0b.

Add tests for IsSurrogate.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/42570043

[gopherbot]

Comment 3 by chanxuehong:

thks all, I found in the same func the "0x3ff" of "surr1 + (r>>10)&0x3ff" can be
removed. 
like this:
return surr1 + r>>10, surr2 + r&0x3ff

[griesemer]

Comment 4:

Re: #3: It's correct that one can remove &0x3ff . Leaving for symmetry (doesn't really
cost).
This was fixed with https://golang.org/cl/42570043 .

Status changed to Fixed.