This CL breaks Go 1 API compatibility but it doesn't matter because
previous ListenUnixgram doesn't work in any use cases, oops.

The public API change is:
-pkg net, func ListenUnixgram(string, *UnixAddr) (*UDPConn, error)
+pkg net, func ListenUnixgram(string, *UnixAddr) (*UnixConn, error)

Fixes #3875.

R=rsc, golang-dev, dave
CC=golang-dev
https://golang.org/cl/6937059

Fixes #4545.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6937058

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/6935059

Delete on a nil map is now a no-op.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6938054

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6948050

Tests that here should be automatic retries if a database
driver's connection returns ErrBadConn on Begin. See
"TestTxErrBadConn" in sql_test.go

R=golang-dev
CC=golang-dev
https://golang.org/cl/6942050

This includes GORACE history_size and log_path flags.

This change is actually an addition to:
https://golang.org/cl/6947046

race_linux_amd64.syso somehow fall out of it.

R=minux.ma
CC=golang-dev
https://golang.org/cl/6946051

This includes GORACE history_size and log_path flags.

R=golang-dev, bradfitz, rsc, remyoudompheng, minux.ma
CC=golang-dev
https://golang.org/cl/6947046

Ignore signals during "go run" and wait for running child
process to exit. Stop executing further tests during "go test",
wait for running tests to exit and report error exit code.

Original CL 6351053 by dfc.

Fixes #3572.
Fixes #3581.

R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/6903061

I just committed a patch to gccgo that notices that float was
never defined, causing an additional unmatched error message.
Rename the type to avoid that message.

R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/6947049

I've been writing some code which involves syncing files (like
rsync) and it became apparent that under Linux I could read
modification times (os.Lstat) with nanosecond precision but
only write them with microsecond precision.  This difference
in precision is rather annoying when trying to discover
whether files need syncing or not!

I've patched syscall and os to increases the accuracy of of
os.Chtimes for Linux and Windows.  This involved exposing the
utimensat system call under Linux and a bit of extra code
under Windows.  I decided not to expose the "at" bit of the
system call as it is impossible to replicate under Windows, so
the patch adds syscall.Utimens() to all architectures along
with a ImplementsUtimens flag.

If the utimensat syscall isn't available (utimensat was added
to Linux in 2.6.22, Released, 8 July 2007) then it silently
falls back to the microsecond accuracy version it uses now.
The improved accuracy for Windows should be good for all
versions of Windows.

Unfortunately Darwin doesn't seem to have a utimensat system
call that I could find so I couldn't implement it there.  The
BSDs do, but since they share their syscall implementation
with Darwin I couldn't figure out how to define a syscall for
*BSD and not Darwin.  I've left this as a TODO in the code.

In the process I implemented the missing methods for Timespec
under Windows which I needed which just happened to round out
the Timespec API for all platforms!

------------------------------------------------------------

Test code: http://play.golang.org/p/1xnGuYOi4b

Linux Before (1000 ns precision)

$ ./utimetest.linux.before z
Setting mtime 1344937903123456789: 2012-08-14 10:51:43.123456789 +0100 BST
Reading mtime 1344937903123457000: 2012-08-14 10:51:43.123457 +0100 BST

Linux After (1 ns precision)

$ ./utimetest.linux.after z
Setting mtime 1344937903123456789: 2012-08-14 10:51:43.123456789 +0100 BST
Reading mtime 1344937903123456789: 2012-08-14 10:51:43.123456789 +0100 BST

Windows Before (1000 ns precision)

X:\>utimetest.windows.before.exe c:\Test.txt
Setting mtime 1344937903123456789: 2012-08-14 10:51:43.123456789 +0100 GMTDT
Reading mtime 1344937903123456000: 2012-08-14 10:51:43.123456 +0100 GMTDT

Windows After (100 ns precision)

X:\>utimetest.windows.after.exe c:\Test.txt
Setting mtime 1344937903123456789: 2012-08-14 10:51:43.123456789 +0100 GMTDT
Reading mtime 1344937903123456700: 2012-08-14 10:51:43.1234567 +0100 GMTDT

R=golang-dev, alex.brainman, rsc, bradfitz
CC=golang-dev
https://golang.org/cl/6905057

Generated by addca.

R=gobot
CC=golang-dev
https://golang.org/cl/6938051

No need for a separate test for this.

R=golang-dev, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6941045

5g: Prog went from 128 bytes to 88 bytes
6g: Prog went from 174 bytes to 144 bytes
8g: Prog went from 124 bytes to 92 bytes

There may be a little more that can be squeezed out of Addr, but alignment will be a factor.

All: remove the unused pun field from Addr

R=rsc, minux.ma
CC=golang-dev
https://golang.org/cl/6922048

Fix the build.

R=golang-dev
CC=golang-dev
https://golang.org/cl/6946044

Fixes #4535.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6942044

Fixes #4539.

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/6942043

Fixes #4392.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6858062

TestDialTimeoutFDLeak will fail when system state somaxconn is
greater than expected fixed value.

Fixes #4384 (again).

R=fullung, dave, rsc
CC=golang-dev
https://golang.org/cl/6873069

Fixes #4530.

R=dvyukov, dave
CC=golang-dev
https://golang.org/cl/6933052

    database/sql: Alter *DB.begin to return driver.ErrBadConn when driver.Conn.Begin returns driver.ErrBadConn
Fixes #4433

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6845094

Generated by addca.

R=gobot
CC=golang-dev
https://golang.org/cl/6939043

Fixes #4467.

The syslog tests can fail if the timeout fires before the data arrives at the mock server. Moving the timeout onto the goroutine that is calling ReadFrom() and always processing the data returned before handling the error should improve the reliability of the test.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6920047

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6934049

Also add style for "Program exited." message.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6934047

Fixes #3814.

R=rsc, iant
CC=golang-dev
https://golang.org/cl/6920057

This is language change. It is a backward-compatible
change but for code that relies on a run-time panic
when calling delete on a nil map (unlikely).

Fixes #4253.

R=rsc, r, iant, ken, bradfitz, rogpeppe
CC=golang-dev
https://golang.org/cl/6909060

Update #4271

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6931052

Fixes #4528

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6922054

Too flaky.

R=iant, rsc
CC=golang-dev
https://golang.org/cl/6925056

Fixes #4145

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6923055

R=r, rsc, iant, ken
CC=golang-dev
https://golang.org/cl/6903048

These are higher-resolution scans of the little
drawings used as clip art on golang.org

R=bradfitz, rsc
CC=golang-dev
https://golang.org/cl/6929058

Credit to Russ for suggesting this fix.

Fixes #3925.

R=golang-dev, franciscossouza, rsc
CC=golang-dev
https://golang.org/cl/6920051

Fixes #4079.

Some example output:

% go install foo/bar
can't load package: package foo/bar: cannot find package "foo/bar" in any of:
        /home/dfc/go/src/pkg/foo/bar (from $GOROOT)
        /home/dfc/src/foo/bar (from $GOPATH)
        /home/dfc/src2/src/foo/bar

% GOPATH= go install foo/bar
can't load package: package foo/bar: cannot find package "foo/bar" in any of:
	/home/dfc/go/src/pkg/foo/bar (from $GOROOT)
	($GOPATH not set)

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6899057

Saves one MOVW and one register during the fast div/mod introduced in CL 6819123.

linux/arm (armv5)

benchmark               old ns/op    new ns/op    delta
BenchmarkInt64Mod1             12           12   +7.50%
BenchmarkUint16Mod2             7            7   +0.28%
BenchmarkUint16Mod4             7            7   -0.28%
BenchmarkUint64Mod1            15           11  -23.72%
BenchmarkInt8Neg                8            7  -17.66%
BenchmarkInt16Neg               8            7  -17.66%
BenchmarkInt32Neg               5            5   -9.04%
BenchmarkUint8Neg               7            6  -14.35%
BenchmarkUint16Neg              8            7  -17.66%
BenchmarkUint32Neg              5            5   -9.04%

R=rsc
CC=golang-dev
https://golang.org/cl/6842045

Implementation suggested by DMorsing.

R=golang-dev, dave, daniel.morsing, rsc
CC=golang-dev
https://golang.org/cl/6903059

Change suggested by iant. The compiler generates
special code for a/b when a is -0x80...0 and b = -1.
A single instruction can cover the case where b is -1,
so only one comparison is needed.

Fixes #3551.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6922049

Fixes #4384.

Implments the suggestion by rsc in comment 15, http://code.google.com/p/go/issues/detail?id=4384#c15

An alternate suggestion would be to temporarily set GOMAXPROCS to 1 during this test.

R=fullung, rsc
CC=golang-dev
https://golang.org/cl/6923046

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/6924050