Rationale:
        It already is for scanning.
        It is accepted for complexes already, but doesn't work.
        It's analogous to %G and %E.
        C accepts it too, and we try to be roughly compatible.
Fixes #7518.

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/77580044

CL 77580046 caused a data race issue with tests that assumes ReadAt
does not mutate receiver. This patch partially revert CL 77580046
to fix it.

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/77900043

These test cases are redundant because TestSimpleFold tests
all possible rotations of test data, so no need to add
rotated strings.

Also updated the comment as it's guaranteed that SimpleFold
returns values in increasing order.

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/77730043

UnreadRune should return an error if previous operation is not
ReadRune.

Fixes #7579.

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/77580046

Also move generated code into a separate file,
because it's difficult to work with the file otherwise.

LGTM=khr
R=golang-codereviews, khr
CC=golang-codereviews
https://golang.org/cl/76080044

If runtime_BeforeFork splits stack, it will unsplit it
with spoiled g->stackguard. It leads to check failure in oldstack:

fatal error: stackfree: bad fixed size

runtime stack:
runtime.throw(0xadf3cd)
runtime.stackfree(0xc208040480, 0xfffffffffffff9dd, 0x1b00fa8)
runtime.oldstack()
runtime.lessstack()

goroutine 311 [stack unsplit]:
syscall.forkAndExecInChild(0xc20802eea0, 0xc208192c00, 0x5, 0x5, 0xc208072a80, ...)
syscall.forkExec(0xc20802ed80, 0x54, 0xc2081ccb40, 0x4, 0x4, ...)

Fixes #7567.

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews, khr, rsc
https://golang.org/cl/77340045

A too large float constant is an error.
A too small float constant is rounded to zero.

Fixes #7419
Update #6902

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/76730046

"go doc" has been removed in CL 17799.

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/77420045

utf8.RuneLen returns -1 for an invalid rune. In that case we
need to extend the internal buffer at least by 3 for \uFFFD.

Fixes #7577.

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/77420044

It's a control character.
Fixes #7565.

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/77300043

Fixes #7249

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/75820046

Fixes #7575

LGTM=iant
R=dvyukov, iant
CC=golang-codereviews
https://golang.org/cl/77540044

See testing.FailNow for further information.
Also avoid nil pointer derefernce in TestTransportMaxPerHostIdleConns.

LGTM=dave
R=golang-codereviews, dave
CC=golang-codereviews
https://golang.org/cl/76470043

"nn" can never be zero for any input "p", so no check is needed.
This change should improve readability a bit.

LGTM=nigeltao
R=golang-codereviews, bradfitz, nigeltao
CC=golang-codereviews
https://golang.org/cl/76610045

Fixes #7013.

LGTM=adg
R=golang-codereviews, gobot, adg
CC=golang-codereviews
https://golang.org/cl/76370043

LGTM=gri, iant
R=gri, iant
CC=golang-codereviews
https://golang.org/cl/75920044

Breaks all builds.

««« original CL description
cmd/gc: Add tests for self-referential array types.

LGTM=gri, iant
R=gri, iant
CC=golang-codereviews
https://golang.org/cl/77050045
»»»

TBR=cmang
R=cmang
CC=golang-codereviews
https://golang.org/cl/77210043

The original test would open a local port and then immediately close it
and use the port number in subsequent tests. Between the port being closed
and reused by the later process, it could be opened by some other program
on the machine.

Changed the test to run the server process directly and have it save the
assigned port to a text file to be used by client processes.

Fixes #5564.

LGTM=adg
R=golang-codereviews, gobot, adg
CC=golang-codereviews
https://golang.org/cl/72290043

LGTM=gri, iant
R=gri, iant
CC=golang-codereviews
https://golang.org/cl/77050045

%q quotes each element of a string slice; this was never explained in the docs.
Fixes #7015.

LGTM=josharian
R=golang-codereviews, josharian
CC=golang-codereviews
https://golang.org/cl/77140044

Fixes #7521.

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/76320043

Generated by addca.

R=gobot
CC=golang-codereviews
https://golang.org/cl/77120044

Request ID reuse is allowed by the FastCGI spec [1]. In particular nginx uses
the same request ID, 1, for all requests on a given connection. Because
serveRequest does not remove the request from conn.requests, this causes it to
treat the second request as a duplicate and drops the connection immediately
after beginRequest. This manifests with nginx option 'fastcgi_keep_conn on' as
the following message in nginx error log:

2014/03/17 01:39:13 [error] 730#0: *109 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: x.x.x.x, server: example.org, request: "GET / HTTP/1.1", upstream: "fastcgi://127.0.0.1:9001", host: "example.org"

Because handleRecord and serveRequest run in different goroutines, access to
conn.requests must now be synchronized.

[1] http://www.fastcgi.com/drupal/node/6?q=node/22#S3.3

LGTM=bradfitz
R=bradfitz
CC=golang-codereviews
https://golang.org/cl/76800043

LGTM=iant
R=iant
CC=golang-codereviews
https://golang.org/cl/76400044

I believe the original author of this code just forgot to check for error here.

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/76760043

"env" is a valid go command. This patch is to make bash to autocomplete it.

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/74660045

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/76930044

Smooth out the setup process for new contributors.

* Remove references $GOROOT (often not defined).
* Add a note for contributing to subrepositories.
* Emphasize that hg mail also uploads the latest copy.

LGTM=adg
R=golang-codereviews, iant, adg
CC=golang-codereviews
https://golang.org/cl/74370043

LGTM=minux.ma
R=golang-codereviews, minux.ma
CC=golang-codereviews
https://golang.org/cl/76270043

See testing.FailNow for further information.

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/75900043

It was using the wrong offset and returned random values
making "runoutput" compiler tests crash.

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/76250043

They were rejected by NaCl due to AES instructions and
accesses to %gs:0x8, caused by wrong tlsoffset value.

LGTM=iant
R=rsc, dave, iant
CC=golang-codereviews
https://golang.org/cl/76050044

It's possible that bgsweep constantly does not catch up for some reason,
in this case runfinq was not woken at all.

R=rsc
CC=golang-codereviews
https://golang.org/cl/75940043

The problem was that spans end up in wrong lists after split
(e.g. in h->busy instead of h->central->empty).
Also the span can be non-swept before split,
I don't know what it can cause, but it's safer to operate on swept spans.
Fixes #7544.

R=golang-codereviews, rsc
CC=golang-codereviews, khr
https://golang.org/cl/76160043

LGTM=rsc
R=rsc, dave, iant, khr
CC=golang-codereviews
https://golang.org/cl/75820044

Currently processes crash with obscure message.
Say that it's "out of memory".

LGTM=rsc
R=golang-codereviews
CC=golang-codereviews, khr, rsc
https://golang.org/cl/75820045

See the comment for description.

LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/75670044

LGTM=rsc
R=golang-codereviews
CC=golang-codereviews, khr, rsc
https://golang.org/cl/76070043

Fixes #7262

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/76110043

Fixes #6405

LGTM=rsc
R=rsc, iant
CC=golang-codereviews
https://golang.org/cl/72920046