This change fixes a few bugs in the HPACK decoder:
 * Excess trailing padding is treated as an error per the HPACK Spec
     section 5.2
 * Non EOS prefix padding is treated as an error
 * Max length is now enforced for all decoded symbols

The idea here is to keep track of the decoded symbol length, rather
than the number of unconsumed bits in cur.  To this end, nbits has
been renamed cbits (cur bits), and sbits (sym bits) has been
introduced.  The main problem with using nbits is that it can easily
be zero, such as when decoding {0xff, 0xff}.  Using a clear moniker
makes it easier to see why checking cbits > 0 at the end of the
function is incorrect.

Fixes golang/go#15614

Change-Id: I1ae868caa9c207fcf9c9dec7f10ee9f400211f99
Reviewed-on: https://go-review.googlesource.com/23067Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Go 1.7 introduces Request.Context and Response.Uncompressed. Use them
both in the http2 Transport when building for Go 1.7.

Tests are in the main repo.

Updates golang/go#15366
Updates golang/go#15134

Change-Id: I4b78a2710b6cf30c769c7f85cea15ecde653a317
Reviewed-on: https://go-review.googlesource.com/23002Reviewed-by: Andrew Gerrand <adg@golang.org>

Change-Id: I62bfc730643cb0756fc67f3c5cf73029b75c07bb
Reviewed-on: https://go-review.googlesource.com/22884Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I7fc0634dd1c7cd49b0f3aa2d84a83e783f6687a1
Reviewed-on: https://go-review.googlesource.com/22678Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I5ceede6cf0aa4fcdbf59c39e1aff9826874f2710
Reviewed-on: https://go-review.googlesource.com/22677Reviewed-by: Ian Lance Taylor <iant@golang.org>

Abbreviating "if and only if" to "iff" is against Go style in public
documentation; use expanded form.

Change-Id: I23afdca1b773ef9572794555dfb768c9ded90ab7
Reviewed-on: https://go-review.googlesource.com/22545Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Fixes golang/go#15449

Change-Id: Ib4802dc1d9208abc17ef31212d49f03f4f4ed3d1
Reviewed-on: https://go-review.googlesource.com/22494Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

But still check that the high bit isn't set.

Fixes golang/go#15444

Change-Id: Ic9339244d3d0c4e4d6573a691b3ba37c9eac3981
Reviewed-on: https://go-review.googlesource.com/22476Reviewed-by: Andrew Gerrand <adg@golang.org>

This was always a no-op in 1.4 and earlier. This change directly
inlines the 1.5 version.

Change-Id: I6dcf69497d876d7dde729c1801cef5382b97fa07
Reviewed-on: https://go-review.googlesource.com/22388Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

The Go 1.4 (and earlier) support for request cancellation is racy and
complicates the implementation of ctxhttp. This change simply inlines
the existing 1.5+ cancellation logic directly, and removes support for
older versions.

Change-Id: I7df9f0648dd0e571366374d079e2976050464ca3
Reviewed-on: https://go-review.googlesource.com/22302Reviewed-by: David Symonds <dsymonds@golang.org>
Run-TryBot: David Symonds <dsymonds@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

9d8ef8d7 caused an extra allocation for gccgo.

Change-Id: I6568d84009882103ec4767546599afa20c54c480
Reviewed-on: https://go-review.googlesource.com/21940Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Updates golang/go#15258

Change-Id: Ieaea9564a6e300938a75d3382151c46e9bde1e59
Reviewed-on: https://go-review.googlesource.com/21903Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I4ce6dfec994252fec3874fb748e0d6b8db97394d
Reviewed-on: https://go-review.googlesource.com/21835Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I1e4133d1988cb745d465b478bcdf01594304e48a
Reviewed-on: https://go-review.googlesource.com/21834Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: Icd29cd883dab0c916e2285d6053074e97771b840
Reviewed-on: https://go-review.googlesource.com/21833Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I88501fc0d84cdcb210bf53a373982c4e399f4c1f
Reviewed-on: https://go-review.googlesource.com/21832Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

Change-Id: I18cc9536444f3112f677f1439a114efe65faf51e
Reviewed-on: https://go-review.googlesource.com/21831Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

In particular, the Property and DeadPropsHolder types need to refer to
the standard xml package, not the internal fork, to be usable by other
packages.

Inside the package, the XML marshaling and unmarshaling is still done by
the etc/internal/xml package, and will remain that way until
https://github.com/golang/go/issues/13400 is resolved.

Fixes golang/go#15128.

Change-Id: Ie7e7927d8b30d97d10b1a4a654d774fdf3e7a1e3
Reviewed-on: https://go-review.googlesource.com/21635Reviewed-by: Andrew Gerrand <adg@golang.org>

There is no semantic change to this commit. A follow-up commit will
change this package's behavior, but this preparatory commit will make
the follow-up's diff smaller, and less noisy.

Change-Id: I12e356fc1f29d3c4a7c3374aab4a1b1eefe01144
Reviewed-on: https://go-review.googlesource.com/21631Reviewed-by: Andrew Gerrand <adg@golang.org>

Change-Id: Ie7422dd04b4d7a14059e33ac19cb82691cff3d3f
Reviewed-on: https://go-review.googlesource.com/21632Reviewed-by: Andrew Gerrand <adg@golang.org>

Change-Id: I078768667f46d413a65a347185a8fb296b9c5b1e
Reviewed-on: https://go-review.googlesource.com/21633Reviewed-by: Andrew Gerrand <adg@golang.org>

During the Go 1.5 development cycle, this package used to require the
standard library's encoding/xml package from Go 1.5 or later, but
https://go-review.googlesource.com/#/c/12772/ (which was submitted in
July 2015) made an internal fork of encoding/xml, as some
namespace related changes introduced in the Go 1.5 cycle were rolled
back in response to https://github.com/golang/go/issues/11841

Thus, this "go1.4" runtime check is no longer necessary. In the long
term, this package should use the standard library's version, and the
internal fork deleted, once https://github.com/golang/go/issues/13400 is
resolved. We could re-introduce a similar check at that time, although
it could be done at compile time (via a "go1.7" build tag) instead of at
runtime.

Change-Id: I18258443aa3d9b519e23106aedb189f25c35495d
Reviewed-on: https://go-review.googlesource.com/21634Reviewed-by: Andrew Gerrand <adg@golang.org>

Fixes golang/go#14214

Change-Id: I474af4735e2135d787e948220a8fcdbba73a2b25
Reviewed-on: https://go-review.googlesource.com/21534Reviewed-by: Andrew Gerrand <adg@golang.org>

Change-Id: I1b0e8812ca5b2e3ca72948d5414d569879e54f35
Reviewed-on: https://go-review.googlesource.com/21461Reviewed-by: Andrew Gerrand <adg@golang.org>

See https://golang.org/cl/20346

Updates golang/go#14660

Change-Id: Ia974e70cdcb240ae1df0018a07595c4d1dcd422a
Reviewed-on: https://go-review.googlesource.com/20347Reviewed-by: Sameer Ajmani <sameer@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>

Adds Keep-Alive to the list of ignored headers in encodeHeaders
as required in the HTTP/2 spec (section 8.1.2.2) and adds a test
to check this.

Fixes golang/go#15085

Change-Id: Ie4624680c5de1f13eb94fa58a2d5d67a02634df3
Reviewed-on: https://go-review.googlesource.com/21482Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The instruction itself doesn't care what the bits it's twiddling represents,
even though the it was introduced to more efficiently manipulate IPv4 packets.

Change-Id: Ie65a6df4041ad2090060636ccf7128680fcf75b7
Reviewed-on: https://go-review.googlesource.com/21244Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>

Change-Id: I87887ea03c36ca7d26e1ab2cb55d723611c942a8
Reviewed-on: https://go-review.googlesource.com/21354Reviewed-by: Ian Lance Taylor <iant@golang.org>

Change-Id: I367d38bca99ede07aa0cf697547c5cb43ce4e164
Reviewed-on: https://go-review.googlesource.com/21353Reviewed-by: Ian Lance Taylor <iant@golang.org>

Backtick is my screen metakey, so this got lost in a copy/paste
at the backtick symbol.

Change-Id: Ia3e7bf5d2819ea83ff6cc86cc3b6210e3f279eb0
Reviewed-on: https://go-review.googlesource.com/21193Reviewed-by: David Symonds <dsymonds@golang.org>

Change-Id: Ied9b2589b4aa5cb445dd368864df047c84848a95
Reviewed-on: https://go-review.googlesource.com/21217Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>

Change-Id: I2fcb07bdc104c488aa61a6c6b6ee8797e60e868a
Reviewed-on: https://go-review.googlesource.com/21216Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>

The code ends up slightly longer, but the decoding is more consistent from
one instruction class to another, so hopefully it's easier to make sense of it.

Change-Id: Ia22c2ebb0865536da0c3dac6876bdb0b20075f04
Reviewed-on: https://go-review.googlesource.com/21215Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

The package currently implements the operations defined by
https://www.kernel.org/doc/Documentation/networking/filter.txt , which
comprises the base BPF virtual machine plus the Linux kernel's extension
opcodes.

Updates golang/go#14982

Change-Id: Iafb43d80e067040e60465a9bfb7d5f2ca90cc2ae
Reviewed-on: https://go-review.googlesource.com/21212Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>

Git rev e7da8eda (CL 20542) introduced an optimization to reuse the
64k request body buffers across multiple requests. But ServeHTTP
handlers could retain them too long and cause races.

Temporarily revert the main part of that CL until a proper fix is in.

Updates golang/go#14960
Updates grpc/grpc-go#604

Change-Id: I28450e797a1d3122868214700b6ef345a0a1a47c
Reviewed-on: https://go-review.googlesource.com/21160Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

The Google GFE replies to HEAD requests with the END_STREAM bit in an
empty DATA frame, not in the response HEADERS. The Go Transport code
mistook this to mean the Content-Length was real.

Worked around in:
https://github.com/GoogleCloudPlatform/gcloud-golang/commit/645322e7db5d89c44d1f3925028479ac7dbc8680

Reported internally in b/27820181.

Change-Id: Id31a047e2277d7d90560fca264919e239ec76d74
Reviewed-on: https://go-review.googlesource.com/21061Reviewed-by: Dave Day <djd@golang.org>

benchmark                        old ns/op     new ns/op     delta
BenchmarkServer_GetRequest-2     259453        256050        -1.31%

benchmark                        old allocs     new allocs     delta
BenchmarkServer_GetRequest-2     24             22             -8.33%

benchmark                        old bytes     new bytes     delta
BenchmarkServer_GetRequest-2     1599          1532          -4.19%

Change-Id: Ieb11a3bd4c752567e0401bcc5e77e027cfb8063c
Reviewed-on: https://go-review.googlesource.com/20999Reviewed-by: Andrew Gerrand <adg@golang.org>

benchmark                        old ns/op     new ns/op     delta
BenchmarkServer_GetRequest-2     269540        259453        -3.74%

benchmark                        old allocs     new allocs     delta
BenchmarkServer_GetRequest-2     25             24             -4.00%

benchmark                        old bytes     new bytes     delta
BenchmarkServer_GetRequest-2     1613          1599          -0.87%

Change-Id: I33609d8fbe2f81e32095fac8b89ddd55592e583f
Reviewed-on: https://go-review.googlesource.com/20998Reviewed-by: Andrew Gerrand <adg@golang.org>

Moves test cases into the test where they're used, to remove
distractions when profiling unrelated tests.

Also this is my style preference, to remove globals and reduce the
scope of variables.

Change-Id: Ie9cd41b16aad9acf5e210f1fb6f19a7fce52180d
Reviewed-on: https://go-review.googlesource.com/20996Reviewed-by: Andrew Gerrand <adg@golang.org>

cancelCtx has an embedded sync.Mutex. This change causes an extra
allocation when creating a new timerCtx via WithDeadline, but that seems
minor when compared with better locking discipline. If it turns out to
be a problem, the whole cancelCtx struct can be flattened into timerCtx.

Addresses part of golang/go#14839.

Change-Id: Ie86ed1b63592b521aefde747d5fafcd49ac18178
Reviewed-on: https://go-review.googlesource.com/20840Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>