lib9: restore printing of signed integers

A casualty of https://codereview.appspot.com/10195044.

If x is an 32-bit int and u is a 64-bit ulong,
        u = (uint)x // converts to uint before extension, so zero fills
        u = (ulong)x // sign-extends

TBR=iant, r
CC=golang-dev
https://codereview.appspot.com/10814043
image/gif: do not allow pixels outside the current palette

After loading a frame of a GIF, check that each pixel
is inside the frame's palette.

Fixes issue 5401.

R=nigeltao, r
CC=golang-dev
https://codereview.appspot.com/10597043

Committer: Nigel Tao <nigeltao@golang.org>
misc/vim: Add compiler plugin for Go

This change adds a basic compiler plugin for Go. The plugin
integrates "go build" with Vim's ":make" command and the
quickfix list.

Fixes issue 5751.

R=golang-dev, dsymonds, niklas.schnelle, 0xjnml
CC=golang-dev
https://codereview.appspot.com/10466043

Committer: David Symonds <dsymonds@golang.org>
sync/atomic: remove test dependency on net/http

Depending on net/http means depending on cgo.
When the tree is in a shaky state it's nice to see sync/atomic
pass even if cgo or net causes broken binaries.

R=golang-dev, dave, r
CC=golang-dev
https://codereview.appspot.com/10753044
runtime: fix memory leaks due to defers
fn can clearly hold a closure in memory.
argp/pc point into stack and so can hold
in memory a block that was previously
a large stack serment.

R=golang-dev, dave, rsc
CC=golang-dev
https://codereview.appspot.com/10784043

Committer: Russ Cox <rsc@golang.org>
runtime: disable preemption

There are various problems, and both Dmitriy and I
will be away for the next week. Make the runtime a bit
more stable while we're gone.

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/10848043
runtime: disable preemption test (fix build)

TBR=golang-dev
CC=golang-dev
https://codereview.appspot.com/10849043
cmd/godoc: set up playground for examples that are already visible

This fixes an issue where linking directly to an example makes it not
runnable and visible only in a tiny window. To see the bug in action,
visit this link: http://golang.org/pkg/strings/#example_Map

R=golang-dev, r
CC=golang-dev
https://codereview.appspot.com/10679050
Merge branch 'master' into gitfix