A+C: Alexander Surma (individual CLA)

Generated by addca.

R=gobot
CC=golang-dev
https://codereview.appspot.com/6951043
A+C: Christopher Cahoon (individual CLA)

Generated by addca.

R=gobot
CC=golang-dev
https://codereview.appspot.com/6947067
cmd/fix: Add keys to printer.Config composite literals.

Fixes issue 4499.

R=rsc
CC=golang-dev
https://codereview.appspot.com/6931046

Committer: Russ Cox <rsc@golang.org>
runtime: struct Obj in mgc0.c and buffers in scanblock()

Details:

- This CL is the conceptual skeleton of code found in CL 6114046

- The garbage collector uses struct Obj to specify memory blocks

- scanblock() is putting found memory blocks into an intermediate buffer
  (xbuf) before adding/flushing them to the main work buffer (wbuf)

- The main loop in scanblock() is replaced with a skeleton code that
  in the future will be able to recognize the type of objects and
  thus will improve the garbage collector's precision.
  For now, all objects are simply sequences of pointers so
  the precision of the garbage collector remains unchanged.

- The code plugs .gcdata and .gcbss sections into the garbage collector.
  scanblock() in this CL is unable to make any use of this.

R=rsc, dvyukov, remyoudompheng
CC=dave, golang-dev, minux.ma
https://codereview.appspot.com/6856121

Committer: Russ Cox <rsc@golang.org>
net/smtp: add optional Hello method

Add a Hello method that allows clients to set the server sent in the EHLO/HELO exchange; the default remains localhost.
Based on CL 5555045 by rsc.

Fixes issue 4219.

R=golang-dev, rsc
CC=golang-dev
https://codereview.appspot.com/6946057

Committer: Russ Cox <rsc@golang.org>
encoding/json: cleanup leftover redundant variables.

Those variables come from ancient times when reflect.Value was
an interface.

R=dave, rsc
CC=golang-dev
https://codereview.appspot.com/6946059
fmt: fix a typo

R=golang-dev, dsymonds
CC=golang-dev
https://codereview.appspot.com/6937065

Committer: David Symonds <dsymonds@golang.org>
cmd/gc: racewalk: fix compiler crash
The code:
func main() {
        v := make([]int64, 10)
        i := 1
        _ = v[(i*4)/3]
}
crashes compiler with:

Program received signal SIGSEGV, Segmentation fault.
0x000000000043c274 in walkexpr (np=0x7fffffffc9b8, init=0x0) at src/cmd/gc/walk.c:587
587			*init = concat(*init, n->ninit);
(gdb) bt
#0  0x000000000043c274 in walkexpr (np=0x7fffffffc9b8, init=0x0) at src/cmd/gc/walk.c:587
#1  0x0000000000432d15 in copyexpr (n=0x7ffff7f69a48, t=<optimized out>, init=0x0) at src/cmd/gc/subr.c:2020
#2  0x000000000043f281 in walkdiv (init=0x0, np=0x7fffffffca70) at src/cmd/gc/walk.c:2901
#3  walkexpr (np=0x7ffff7f69760, init=0x0) at src/cmd/gc/walk.c:956
#4  0x000000000043d801 in walkexpr (np=0x7ffff7f69bc0, init=0x0) at src/cmd/gc/walk.c:988
#5  0x000000000043cc9b in walkexpr (np=0x7ffff7f69d38, init=0x0) at src/cmd/gc/walk.c:1068
#6  0x000000000043c50b in walkexpr (np=0x7ffff7f69f50, init=0x0) at src/cmd/gc/walk.c:879
#7  0x000000000043c50b in walkexpr (np=0x7ffff7f6a0c8, init=0x0) at src/cmd/gc/walk.c:879
#8  0x0000000000440a53 in walkexprlist (l=0x7ffff7f6a0c8, init=0x0) at src/cmd/gc/walk.c:357
#9  0x000000000043d0bf in walkexpr (np=0x7fffffffd318, init=0x0) at src/cmd/gc/walk.c:566
#10 0x00000000004402bf in vmkcall (fn=<optimized out>, t=0x0, init=0x0, va=0x7fffffffd368) at src/cmd/gc/walk.c:2275
#11 0x000000000044059a in mkcall (name=<optimized out>, t=0x0, init=0x0) at src/cmd/gc/walk.c:2287
#12 0x000000000042862b in callinstr (np=0x7fffffffd4c8, init=0x7fffffffd568, wr=0, skip=<optimized out>) at src/cmd/gc/racewalk.c:478
#13 0x00000000004288b7 in racewalknode (np=0x7ffff7f68108, init=0x7fffffffd568, wr=0, skip=0) at src/cmd/gc/racewalk.c:287
#14 0x0000000000428781 in racewalknode (np=0x7ffff7f65840, init=0x7fffffffd568, wr=0, skip=0) at src/cmd/gc/racewalk.c:302
#15 0x0000000000428abd in racewalklist (l=0x7ffff7f65840, init=0x0) at src/cmd/gc/racewalk.c:97
#16 0x0000000000428d0b in racewalk (fn=0x7ffff7f5f010) at src/cmd/gc/racewalk.c:63
#17 0x0000000000402b9c in compile (fn=0x7ffff7f5f010) at src/cmd/6g/../gc/pgen.c:67
#18 0x0000000000419f86 in funccompile (n=0x7ffff7f5f010, isclosure=0) at src/cmd/gc/dcl.c:1414
#19 0x0000000000424161 in p9main (argc=<optimized out>, argv=<optimized out>) at src/cmd/gc/lex.c:431
#20 0x0000000000401739 in main (argc=<optimized out>, argv=<optimized out>) at src/lib9/main.c:35

The problem is nil init passed to mkcall().

R=golang-dev, rsc
CC=golang-dev
https://codereview.appspot.com/6940045