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diff --git a/go/golang/go/doc/go1.8.html b/go/golang/go/doc/go1.8.html new file mode 100644 index 00000000..611f5ee2 --- /dev/null +++ b/go/golang/go/doc/go1.8.html @@ -0,0 +1,1666 @@ +<!--{ + "Title": "Go 1.8 Release Notes", + "Path": "/doc/go1.8", + "Template": true +}--> + +<!-- +NOTE: In this document and others in this directory, the convention is to +set fixed-width phrases with non-fixed-width spaces, as in +<code>hello</code> <code>world</code>. +Do not send CLs removing the interior tags from such phrases. +--> + +<style> +ul li { margin: 0.5em 0; } +</style> + +<h2 id="introduction">Introduction to Go 1.8</h2> + +<p> +The latest Go release, version 1.8, arrives six months after <a href="go1.7">Go 1.7</a>. +Most of its changes are in the implementation of the toolchain, runtime, and libraries. +There are <a href="#language">two minor changes</a> to the language specification. +As always, the release maintains the Go 1 <a href="/doc/go1compat.html">promise of compatibility</a>. +We expect almost all Go programs to continue to compile and run as before. +</p> + +<p> +The release <a href="#ports">adds support for 32-bit MIPS</a>, +<a href="#compiler">updates the compiler back end</a> to generate more efficient code, +<a href="#gc">reduces GC pauses</a> by eliminating stop-the-world stack rescanning, +<a href="#h2push">adds HTTP/2 Push support</a>, +<a href="#http_shutdown">adds HTTP graceful shutdown</a>, +<a href="#more_context">adds more context support</a>, +<a href="#mutex_prof">enables profiling mutexes</a>, +and <a href="#sort_slice">simplifies sorting slices</a>. +</p> + +<h2 id="language">Changes to the language</h2> + +<p> + When explicitly converting a value from one struct type to another, + as of Go 1.8 the tags are ignored. Thus two structs that differ + only in their tags may be converted from one to the other: +</p> + +<pre> +func example() { + type T1 struct { + X int `json:"foo"` + } + type T2 struct { + X int `json:"bar"` + } + var v1 T1 + var v2 T2 + v1 = T1(v2) // now legal +} +</pre> + + +<p> <!-- CL 17711 --> + The language specification now only requires that implementations + support up to 16-bit exponents in floating-point constants. This does not affect + either the “<a href="/cmd/compile/"><code>gc</code></a>” or + <code>gccgo</code> compilers, both of + which still support 32-bit exponents. +</p> + +<h2 id="ports">Ports</h2> + +<p> +Go now supports 32-bit MIPS on Linux for both big-endian +(<code>linux/mips</code>) and little-endian machines +(<code>linux/mipsle</code>) that implement the MIPS32r1 instruction set with FPU +or kernel FPU emulation. Note that many common MIPS-based routers lack an FPU and +have firmware that doesn't enable kernel FPU emulation; Go won't run on such machines. +</p> + +<p> +On DragonFly BSD, Go now requires DragonFly 4.4.4 or later. <!-- CL 29491, CL 29971 --> +</p> + +<p> +On OpenBSD, Go now requires OpenBSD 5.9 or later. <!-- CL 34093 --> +</p> + +<p> +The Plan 9 port's networking support is now much more complete +and matches the behavior of Unix and Windows with respect to deadlines +and cancelation. For Plan 9 kernel requirements, see the +<a href="https://golang.org/wiki/Plan9">Plan 9 wiki page</a>. +</p> + +<p> + Go 1.8 now only supports OS X 10.8 or later. This is likely the last + Go release to support 10.8. Compiling Go or running + binaries on older OS X versions is untested. +</p> + +<p> + Go 1.8 will be the last release to support Linux on ARMv5E and ARMv6 processors: + Go 1.9 will likely require the ARMv6K (as found in the Raspberry Pi 1) or later. + To identify whether a Linux system is ARMv6K or later, run + “<code>go</code> <code>tool</code> <code>dist</code> <code>-check-armv6k</code>” + (to facilitate testing, it is also possible to just copy the <code>dist</code> command to the + system without installing a full copy of Go 1.8) + and if the program terminates with output "ARMv6K supported." then the system + implements ARMv6K or later. + Go on non-Linux ARM systems already requires ARMv6K or later. +</p> + + +<h3 id="known_issues">Known Issues</h3> + +<p> +There are some instabilities on FreeBSD and NetBSD that are known but not understood. +These can lead to program crashes in rare cases. +See +<a href="https://golang.org/issue/15658">issue 15658</a> and +<a href="https://golang.org/issue/16511">issue 16511</a>. +Any help in solving these issues would be appreciated. +</p> + +<h2 id="tools">Tools</h2> + +<h3 id="cmd_asm">Assembler</h3> + +<p> +For 64-bit x86 systems, the following instructions have been added: +<code>VBROADCASTSD</code>, +<code>BROADCASTSS</code>, +<code>MOVDDUP</code>, +<code>MOVSHDUP</code>, +<code>MOVSLDUP</code>, +<code>VMOVDDUP</code>, +<code>VMOVSHDUP</code>, and +<code>VMOVSLDUP</code>. +</p> + +<p> +For 64-bit PPC systems, the common vector scalar instructions have been +added: +<code>LXS</code>, +<code>LXSDX</code>, +<code>LXSI</code>, +<code>LXSIWAX</code>, +<code>LXSIWZX</code>, +<code>LXV</code>, +<code>LXVD2X</code>, +<code>LXVDSX</code>, +<code>LXVW4X</code>, +<code>MFVSR</code>, +<code>MFVSRD</code>, +<code>MFVSRWZ</code>, +<code>MTVSR</code>, +<code>MTVSRD</code>, +<code>MTVSRWA</code>, +<code>MTVSRWZ</code>, +<code>STXS</code>, +<code>STXSDX</code>, +<code>STXSI</code>, +<code>STXSIWX</code>, +<code>STXV</code>, +<code>STXVD2X</code>, +<code>STXVW4X</code>, +<code>XSCV</code>, +<code>XSCVDPSP</code>, +<code>XSCVDPSPN</code>, +<code>XSCVDPSXDS</code>, +<code>XSCVDPSXWS</code>, +<code>XSCVDPUXDS</code>, +<code>XSCVDPUXWS</code>, +<code>XSCVSPDP</code>, +<code>XSCVSPDPN</code>, +<code>XSCVSXDDP</code>, +<code>XSCVSXDSP</code>, +<code>XSCVUXDDP</code>, +<code>XSCVUXDSP</code>, +<code>XSCVX</code>, +<code>XSCVXP</code>, +<code>XVCV</code>, +<code>XVCVDPSP</code>, +<code>XVCVDPSXDS</code>, +<code>XVCVDPSXWS</code>, +<code>XVCVDPUXDS</code>, +<code>XVCVDPUXWS</code>, +<code>XVCVSPDP</code>, +<code>XVCVSPSXDS</code>, +<code>XVCVSPSXWS</code>, +<code>XVCVSPUXDS</code>, +<code>XVCVSPUXWS</code>, +<code>XVCVSXDDP</code>, +<code>XVCVSXDSP</code>, +<code>XVCVSXWDP</code>, +<code>XVCVSXWSP</code>, +<code>XVCVUXDDP</code>, +<code>XVCVUXDSP</code>, +<code>XVCVUXWDP</code>, +<code>XVCVUXWSP</code>, +<code>XVCVX</code>, +<code>XVCVXP</code>, +<code>XXLAND</code>, +<code>XXLANDC</code>, +<code>XXLANDQ</code>, +<code>XXLEQV</code>, +<code>XXLNAND</code>, +<code>XXLNOR</code>, +<code>XXLOR</code>, +<code>XXLORC</code>, +<code>XXLORQ</code>, +<code>XXLXOR</code>, +<code>XXMRG</code>, +<code>XXMRGHW</code>, +<code>XXMRGLW</code>, +<code>XXPERM</code>, +<code>XXPERMDI</code>, +<code>XXSEL</code>, +<code>XXSI</code>, +<code>XXSLDWI</code>, +<code>XXSPLT</code>, and +<code>XXSPLTW</code>. +</p> + +<h3 id="tool_yacc">Yacc</h3> + +<p> <!-- CL 27324, CL 27325 --> +The <code>yacc</code> tool (previously available by running +“<code>go</code> <code>tool</code> <code>yacc</code>”) has been removed. +As of Go 1.7 it was no longer used by the Go compiler. +It has moved to the “tools” repository and is now available at +<code><a href="https://godoc.org/golang.org/x/tools/cmd/goyacc">golang.org/x/tools/cmd/goyacc</a></code>. +</p> + +<h3 id="tool_fix">Fix</h3> + +<p> <!-- CL 28872 --> + The <code>fix</code> tool has a new “<code>context</code>” + fix to change imports from “<code>golang.org/x/net/context</code>” + to “<a href="/pkg/context/"><code>context</code></a>”. +</p> + +<h3 id="tool_pprof">Pprof</h3> + +<p> <!-- CL 33157 --> + The <code>pprof</code> tool can now profile TLS servers + and skip certificate validation by using the “<code>https+insecure</code>” + URL scheme. +</p> + +<p> <!-- CL 23781 --> + The callgrind output now has instruction-level granularity. +</p> + +<h3 id="tool_trace">Trace</h3> + +<p> <!-- CL 23324 --> + The <code>trace</code> tool has a new <code>-pprof</code> flag for + producing pprof-compatible blocking and latency profiles from an + execution trace. +</p> + +<p> <!-- CL 30017, CL 30702 --> + Garbage collection events are now shown more clearly in the + execution trace viewer. Garbage collection activity is shown on its + own row and GC helper goroutines are annotated with their roles. +</p> + +<h3 id="tool_vet">Vet</h3> + +<p>Vet is stricter in some ways and looser where it + previously caused false positives.</p> + +<p>Vet now checks for copying an array of locks, + duplicate JSON and XML struct field tags, + non-space-separated struct tags, + deferred calls to HTTP <code>Response.Body.Close</code> + before checking errors, and + indexed arguments in <code>Printf</code>. + It also improves existing checks.</p> +</p> + +<h3 id="compiler">Compiler Toolchain</h3> + +<p> +Go 1.7 introduced a new compiler back end for 64-bit x86 systems. +In Go 1.8, that back end has been developed further and is now used for +all architectures. +</p> + +<p> +The new back end, based on +<a href="https://en.wikipedia.org/wiki/Static_single_assignment_form">static single assignment form</a> (SSA), +generates more compact, more efficient code +and provides a better platform for optimizations +such as bounds check elimination. +The new back end reduces the CPU time required by +<a href="https://golang.org/test/bench/go1/">our benchmark programs</a> by 20-30% +on 32-bit ARM systems. For 64-bit x86 systems, which already used the SSA back end in +Go 1.7, the gains are a more modest 0-10%. Other architectures will likely +see improvements closer to the 32-bit ARM numbers. +</p> + +<p> + The temporary <code>-ssa=0</code> compiler flag introduced in Go 1.7 + to disable the new back end has been removed in Go 1.8. +</p> + +<p> + In addition to enabling the new compiler back end for all systems, + Go 1.8 also introduces a new compiler front end. The new compiler + front end should not be noticeable to users but is the foundation for + future performance work. +</p> + +<p> + The compiler and linker have been optimized and run faster in this + release than in Go 1.7, although they are still slower than we would + like and will continue to be optimized in future releases. + Compared to the previous release, Go 1.8 is + <a href="https://dave.cheney.net/2016/11/19/go-1-8-toolchain-improvements">about 15% faster</a>. +</p> + +<h3 id="cmd_cgo">Cgo</h3> + +<p> <!-- CL 31141 --> +The Go tool now remembers the value of the <code>CGO_ENABLED</code> environment +variable set during <code>make.bash</code> and applies it to all future compilations +by default to fix issue <a href="https://golang.org/issue/12808">#12808</a>. +When doing native compilation, it is rarely necessary to explicitly set +the <code>CGO_ENABLED</code> environment variable as <code>make.bash</code> +will detect the correct setting automatically. The main reason to explicitly +set the <code>CGO_ENABLED</code> environment variable is when your environment +supports cgo, but you explicitly do not want cgo support, in which case, set +<code>CGO_ENABLED=0</code> during <code>make.bash</code> or <code>all.bash</code>. +</p> + +<p> <!-- CL 29991 --> +The environment variable <code>PKG_CONFIG</code> may now be used to +set the program to run to handle <code>#cgo</code> <code>pkg-config</code> +directives. The default is <code>pkg-config</code>, the program +always used by earlier releases. This is intended to make it easier +to cross-compile +<a href="/cmd/cgo/">cgo</a> code. +</p> + +<p> <!-- CL 32354 --> +The <a href="/cmd/cgo/">cgo</a> tool now supports a <code>-srcdir</code> +option, which is used by the <a href="/cmd/go/">go</a> command. +</p> + +<p> <!-- CL 31768, 31811 --> +If <a href="/cmd/cgo/">cgo</a> code calls <code>C.malloc</code>, and +<code>malloc</code> returns <code>NULL</code>, the program will now +crash with an out of memory error. +<code>C.malloc</code> will never return <code>nil</code>. +Unlike most C functions, <code>C.malloc</code> may not be used in a +two-result form returning an errno value. +</p> + +<p> <!-- CL 33237 --> +If <a href="/cmd/cgo/">cgo</a> is used to call a C function passing a +pointer to a C union, and if the C union can contain any pointer +values, and if <a href="/cmd/cgo/#hdr-Passing_pointers">cgo pointer +checking</a> is enabled (as it is by default), the union value is now +checked for Go pointers. +</p> + +<h3 id="gccgo">Gccgo</h3> + +<p> +Due to the alignment of Go's semiannual release schedule with GCC's +annual release schedule, +GCC release 6 contains the Go 1.6.1 version of gccgo. +We expect that the next release, GCC 7, will contain the Go 1.8 +version of gccgo. +</p> + +<h3 id="gopath">Default GOPATH</h3> + +<p> + The + <a href="/cmd/go/#hdr-GOPATH_environment_variable"><code>GOPATH</code> + environment variable</a> now has a default value if it + is unset. It defaults to + <code>$HOME/go</code> on Unix and + <code>%USERPROFILE%/go</code> on Windows. +</p> + +<h3 id="go_get">Go get</h3> + +<p> <!-- CL 34818 --> + The “<code>go</code> <code>get</code>” command now always respects + HTTP proxy environment variables, regardless of whether + the <code style='white-space:nowrap'>-insecure</code> flag is used. In previous releases, the + <code style='white-space:nowrap'>-insecure</code> flag had the side effect of not using proxies. +</p> + +<h3 id="go_bug">Go bug</h3> + +<p> + The new + “<a href="/cmd/go/#hdr-Print_information_for_bug_reports"><code>go</code> <code>bug</code></a>” + command starts a bug report on GitHub, prefilled + with information about the current system. +</p> + +<h3 id="cmd_doc">Go doc</h3> + +<p> <!-- CL 25419 --> + The + “<a href="/cmd/go/#hdr-Show_documentation_for_package_or_symbol"><code>go</code> <code>doc</code></a>” + command now groups constants and variables with their type, + following the behavior of + <a href="/cmd/godoc/"><code>godoc</code></a>. +</p> + +<p> <!-- CL 25420 --> + In order to improve the readability of <code>doc</code>'s + output, each summary of the first-level items is guaranteed to + occupy a single line. +</p> + +<p> <!-- CL 31852 --> + Documentation for a specific method in an interface definition can + now be requested, as in + “<code>go</code> <code>doc</code> <code>net.Conn.SetDeadline</code>”. +</p> + +<h3 id="plugin">Plugins</h3> + +<p> + Go now provides early support for plugins with a “<code>plugin</code>” + build mode for generating plugins written in Go, and a + new <a href="/pkg/plugin/"><code>plugin</code></a> package for + loading such plugins at run time. Plugin support is currently only + available on Linux. Please report any issues. +</p> + +<h2 id="runtime">Runtime</h2> + +<h3 id="liveness">Argument Liveness</h3> + +<p> + <!-- Issue 15843 --> The garbage collector no longer considers + arguments live throughout the entirety of a function. For more + information, and for how to force a variable to remain live, see + the <a href="/pkg/runtime/#KeepAlive"><code>runtime.KeepAlive</code></a> + function added in Go 1.7. +</p> + +<p> + <i>Updating:</i> + Code that sets a finalizer on an allocated object may need to add + calls to <code>runtime.KeepAlive</code> in functions or methods + using that object. + Read the + <a href="/pkg/runtime/#KeepAlive"><code>KeepAlive</code> + documentation</a> and its example for more details. +</p> + +<h3 id="mapiter">Concurrent Map Misuse</h3> + +<p> +In Go 1.6, the runtime +<a href="/doc/go1.6#runtime">added lightweight, +best-effort detection of concurrent misuse of maps</a>. This release +improves that detector with support for detecting programs that +concurrently write to and iterate over a map. +</p> +<p> +As always, if one goroutine is writing to a map, no other goroutine should be +reading (which includes iterating) or writing the map concurrently. +If the runtime detects this condition, it prints a diagnosis and crashes the program. +The best way to find out more about the problem is to run the program +under the +<a href="https://blog.golang.org/race-detector">race detector</a>, +which will more reliably identify the race +and give more detail. +</p> + +<h3 id="memstats">MemStats Documentation</h3> + +<p> <!-- CL 28972 --> + The <a href="/pkg/runtime/#MemStats"><code>runtime.MemStats</code></a> + type has been more thoroughly documented. +</p> + +<h2 id="performance">Performance</h2> + +<p> +As always, the changes are so general and varied that precise statements +about performance are difficult to make. +Most programs should run a bit faster, +due to speedups in the garbage collector and +optimizations in the standard library. +</p> + +<p> +There have been optimizations to implementations in the +<a href="/pkg/bytes/"><code>bytes</code></a>, +<a href="/pkg/crypto/aes/"><code>crypto/aes</code></a>, +<a href="/pkg/crypto/cipher/"><code>crypto/cipher</code></a>, +<a href="/pkg/crypto/elliptic/"><code>crypto/elliptic</code></a>, +<a href="/pkg/crypto/sha256/"><code>crypto/sha256</code></a>, +<a href="/pkg/crypto/sha512/"><code>crypto/sha512</code></a>, +<a href="/pkg/encoding/asn1/"><code>encoding/asn1</code></a>, +<a href="/pkg/encoding/csv/"><code>encoding/csv</code></a>, +<a href="/pkg/encoding/hex/"><code>encoding/hex</code></a>, +<a href="/pkg/encoding/json/"><code>encoding/json</code></a>, +<a href="/pkg/hash/crc32/"><code>hash/crc32</code></a>, +<a href="/pkg/image/color/"><code>image/color</code></a>, +<a href="/pkg/image/draw/"><code>image/draw</code></a>, +<a href="/pkg/math/"><code>math</code></a>, +<a href="/pkg/math/big/"><code>math/big</code></a>, +<a href="/pkg/reflect/"><code>reflect</code></a>, +<a href="/pkg/regexp/"><code>regexp</code></a>, +<a href="/pkg/runtime/"><code>runtime</code></a>, +<a href="/pkg/strconv/"><code>strconv</code></a>, +<a href="/pkg/strings/"><code>strings</code></a>, +<a href="/pkg/syscall/"><code>syscall</code></a>, +<a href="/pkg/text/template/"><code>text/template</code></a>, and +<a href="/pkg/unicode/utf8/"><code>unicode/utf8</code></a> +packages. +</p> + +<h3 id="gc">Garbage Collector</h3> + +<p> + Garbage collection pauses should be significantly shorter than they + were in Go 1.7, usually under 100 microseconds and often as low as + 10 microseconds. + See the + <a href="https://github.com/golang/proposal/blob/master/design/17503-eliminate-rescan.md" + >document on eliminating stop-the-world stack re-scanning</a> + for details. More work remains for Go 1.9. +</p> + +<h3 id="defer">Defer</h3> + +<!-- CL 29656, CL 29656 --> +<p> + The overhead of <a href="/ref/spec/#Defer_statements">deferred + function calls</a> has been reduced by about half. +</p> + +<h3 id="cgoperf">Cgo</h3> + +<p>The overhead of calls from Go into C has been reduced by about half.</p> + +<h2 id="library">Standard library</h2> + +<h3 id="examples">Examples</h3> + +<p> +Examples have been added to the documentation across many packages. +</p> + +<h3 id="sort_slice">Sort</h3> + +<p> +The <a href="/pkg/sort/">sort</a> package +now includes a convenience function +<a href="/pkg/sort/#Slice"><code>Slice</code></a> to sort a +slice given a <em>less</em> function. + +In many cases this means that writing a new sorter type is not +necessary. +</p> + +<p> +Also new are +<a href="/pkg/sort/#SliceStable"><code>SliceStable</code></a> and +<a href="/pkg/sort/#SliceIsSorted"><code>SliceIsSorted</code></a>. +</p> + +<h3 id="h2push">HTTP/2 Push</h3> + +<p> +The <a href="/pkg/net/http/">net/http</a> package now includes a +mechanism to +send HTTP/2 server pushes from a +<a href="/pkg/net/http/#Handler"><code>Handler</code></a>. +Similar to the existing <code>Flusher</code> and <code>Hijacker</code> +interfaces, an HTTP/2 +<a href="/pkg/net/http/#ResponseWriter"><code>ResponseWriter</code></a> +now implements the new +<a href="/pkg/net/http/#Pusher"><code>Pusher</code></a> interface. +</p> + +<h3 id="http_shutdown">HTTP Server Graceful Shutdown</h3> + +<p> <!-- CL 32329 --> + The HTTP Server now has support for graceful shutdown using the new + <a href="/pkg/net/http/#Server.Shutdown"><code>Server.Shutdown</code></a> + method and abrupt shutdown using the new + <a href="/pkg/net/http/#Server.Close"><code>Server.Close</code></a> + method. +</p> + +<h3 id="more_context">More Context Support</h3> + +<p> + Continuing <a href="/doc/go1.7#context">Go 1.7's adoption</a> + of <a href="/pkg/context/#Context"><code>context.Context</code></a> + into the standard library, Go 1.8 adds more context support + to existing packages: +</p> + +<ul> + <li>The new <a href="/pkg/net/http/#Server.Shutdown"><code>Server.Shutdown</code></a> + takes a context argument.</li> + <li>There have been <a href="#database_sql">significant additions</a> to the + <a href="/pkg/database/sql/">database/sql</a> package with context support.</li> + <li>All nine of the new <code>Lookup</code> methods on the new + <a href="/pkg/net/#Resolver"><code>net.Resolver</code></a> now + take a context.</li> + </ul> + +<h3 id="mutex_prof">Mutex Contention Profiling</h3> + +<p> + The runtime and tools now support profiling contended mutexes. +</p> + +<p> + Most users will want to use the new <code>-mutexprofile</code> + flag with “<a href="/cmd/go/#hdr-Description_of_testing_flags"><code>go</code> <code>test</code></a>”, + and then use <a href="/cmd/pprof/">pprof</a> on the resultant file. +</p> + +<p> + Lower-level support is also available via the new + <a href="/pkg/runtime/#MutexProfile"><code>MutexProfile</code></a> + and + <a href="/pkg/runtime/#SetMutexProfileFraction"><code>SetMutexProfileFraction</code></a>. +</p> + +<p> + A known limitation for Go 1.8 is that the profile only reports contention for + <a href="/pkg/sync/#Mutex"><code>sync.Mutex</code></a>, + not + <a href="/pkg/sync/#RWMutex"><code>sync.RWMutex</code></a>. +</p> + +<h3 id="minor_library_changes">Minor changes to the library</h3> + +<p> +As always, there are various minor changes and updates to the library, +made with the Go 1 <a href="/doc/go1compat">promise of compatibility</a> +in mind. The following sections list the user visible changes and additions. +Optimizations and minor bug fixes are not listed. +</p> + +<dl id="archive_tar"><dt><a href="/pkg/archive/tar/">archive/tar</a></dt> + <dd> + + <p> <!-- CL 28471, CL 31440, CL 31441, CL 31444, CL 28418, CL 31439 --> + The tar implementation corrects many bugs in corner cases of the file format. + The <a href="/pkg/archive/tar/#Reader"><code>Reader</code></a> + is now able to process tar files in the PAX format with entries larger than 8GB. + The <a href="/pkg/archive/tar/#Writer"><code>Writer</code></a> + no longer produces invalid tar files in some situations involving long pathnames. + </p> + + </dd> +</dl> + +<dl id="compress_flate"><dt><a href="/pkg/compress/flate/">compress/flate</a></dt> + <dd> + + <p> <!-- CL 31640, CL 31174, CL 32149 --> + There have been some minor fixes to the encoder to improve the + compression ratio in certain situations. As a result, the exact + encoded output of <code>DEFLATE</code> may be different from Go 1.7. Since + <code>DEFLATE</code> is the underlying compression of gzip, png, zlib, and zip, + those formats may have changed outputs. + </p> + + <p> <!-- CL 31174 --> + The encoder, when operating in + <a href="/pkg/compress/flate/#NoCompression"><code>NoCompression</code></a> + mode, now produces a consistent output that is not dependent on + the size of the slices passed to the + <a href="/pkg/compress/flate/#Writer.Write"><code>Write</code></a> + method. + </p> + + <p> <!-- CL 28216 --> + The decoder, upon encountering an error, now returns any + buffered data it had uncompressed along with the error. + </p> + + </dd> +</dl> + + +<dl id="compress_gzip"><dt><a href="/pkg/compress/gzip/">compress/gzip</a></dt> + <dd> + + <p> + The <a href="/pkg/compress/gzip/#Writer"><code>Writer</code></a> + now encodes a zero <code>MTIME</code> field when + the <a href="/pkg/compress/gzip/#Header"><code>Header.ModTime</code></a> + field is the zero value. + + In previous releases of Go, the <code>Writer</code> would encode + a nonsensical value. + + Similarly, + the <a href="/pkg/compress/gzip/#Reader"><code>Reader</code></a> + now reports a zero encoded <code>MTIME</code> field as a zero + <code>Header.ModTime</code>. + </p> + + </dd> +</dl> + +<dl id="context"><dt><a href="/pkg/context/">context</a></dt> + <dd> + <p> <!-- CL 30370 --> + The <a href="/pkg/context#DeadlineExceeded"><code>DeadlineExceeded</code></a> + error now implements + <a href="/pkg/net/#Error"><code>net.Error</code></a> + and reports true for both the <code>Timeout</code> and + <code>Temporary</code> methods. + </p> + </dd> +</dl> + +<dl id="crypto_tls"><dt><a href="/pkg/crypto/tls/">crypto/tls</a></dt> + <dd> + <p> <!-- CL 25159, CL 31318 --> + The new method + <a href="/pkg/crypto/tls/#Conn.CloseWrite"><code>Conn.CloseWrite</code></a> + allows TLS connections to be half closed. + </p> + + <p> <!-- CL 28075 --> + The new method + <a href="/pkg/crypto/tls/#Config.Clone"><code>Config.Clone</code></a> + clones a TLS configuration. + </p> + + <p> + <!-- CL 30790 --> + The new <a href="/pkg/crypto/tls/#Config.GetConfigForClient"><code>Config.GetConfigForClient</code></a> + callback allows selecting a configuration for a client dynamically, based + on the client's + <a href="/pkg/crypto/tls/#ClientHelloInfo"><code>ClientHelloInfo</code></a>. + + <!-- CL 31391, CL 32119 --> + The <a href="/pkg/crypto/tls/#ClientHelloInfo"><code>ClientHelloInfo</code></a> + struct now has new + fields <code>Conn</code>, <code>SignatureSchemes</code> (using + the new + type <a href="/kg/crypto/tls/#SignatureScheme"><code>SignatureScheme</code></a>), + <code>SupportedProtos</code>, and <code>SupportedVersions</code>. + </p> + + <p> <!-- CL 32115 --> + The new <a href="/pkg/crypto/tls/#Config.GetClientCertificate"><code>Config.GetClientCertificate</code></a> + callback allows selecting a client certificate based on the server's + TLS <code>CertificateRequest</code> message, represented by the new + <a href="/pkg/crypto/tls/#CertificateRequestInfo"><code>CertificateRequestInfo</code></a>. + </p> + + <p> <!-- CL 27434 --> + The new + <a href="/pkg/crypto/tls/#Config.KeyLogWriter"><code>Config.KeyLogWriter</code></a> + allows debugging TLS connections + in <a href="https://www.wireshark.org/">WireShark</a> and + similar tools. + </p> + + <p> <!-- CL 32115 --> + The new + <a href="/pkg/crypto/tls/#Config.VerifyPeerCertificate"><code>Config.VerifyPeerCertificate</code></a> + callback allows additional validation of a peer's presented certificate. + </p> + + <p> <!-- CL 18130 --> + The <code>crypto/tls</code> package now implements basic + countermeasures against CBC padding oracles. There should be + no explicit secret-dependent timings, but it does not attempt to + normalize memory accesses to prevent cache timing leaks. + </p> + + <p> + The <code>crypto/tls</code> package now supports + X25519 and <!-- CL 30824, CL 30825 --> + ChaCha20-Poly1305. <!-- CL 30957, CL 30958 --> + ChaCha20-Poly1305 is now prioritized unless <!-- CL 32871 --> + hardware support for AES-GCM is present. + </p> + + <p> <!-- CL 27315, CL 35290 --> + AES-128-CBC cipher suites with SHA-256 are also + now supported, but disabled by default. + </p> + + </dd> +</dl> + +<dl id="crypto_x509"><dt><a href="/pkg/crypto/x509/">crypto/x509</a></dt> + <dd> + <p> <!-- CL 24743 --> + PSS signatures are now supported. + </p> + + <p> <!-- CL 32644 --> + <a href="/pkg/crypto/x509/#UnknownAuthorityError"><code>UnknownAuthorityError</code></a> + now has a <code>Cert</code> field, reporting the untrusted + certificate. + </p> + + <p> + Certificate validation is more permissive in a few cases and + stricter in a few other cases. + <!-- +crypto/x509: allow a leaf certificate to be specified directly as root (CL 27393) +crypto/x509: check that the issuer name matches the issuer's subject name (CL 23571) +crypto/x509: don't accept a root that already appears in a chain. (CL 32121) +crypto/x509: fix name constraints handling (CL 30155) +crypto/x509: parse all names in an RDN (CL 30810) +crypto/x509: recognise ISO OID for RSA+SHA1 (CL 27394) +crypto/x509: require a NULL parameters for RSA public keys (CL 16166, CL 27312) +crypto/x509: return error for missing SerialNumber (CL 27238) +--> + </p> + + <p><!-- CL 30375 --> + Root certificates will now also be looked for + at <code>/etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem</code> + on Linux, to support RHEL and CentOS. + </p> + + </dd> +</dl> + +<dl id="database_sql"><dt><a href="/pkg/database/sql/">database/sql</a></dt> + <dd> + <p> + The package now supports <code>context.Context</code>. There are new methods + ending in <code>Context</code> such as + <a href="/pkg/database/sql/#DB.QueryContext"><code>DB.QueryContext</code></a> and + <a href="/pkg/database/sql/#DB.PrepareContext"><code>DB.PrepareContext</code></a> + that take context arguments. Using the new <code>Context</code> methods ensures that + connections are closed and returned to the connection pool when the + request is done; enables canceling in-progress queries + should the driver support that; and allows the database + pool to cancel waiting for the next available connection. + </p> + <p> + The <a href="/pkg/database/sql#IsolationLevel"><code>IsolationLevel</code></a> + can now be set when starting a transaction by setting the isolation level + on <a href="/pkg/database/sql#TxOptions.Isolation"><code>TxOptions.Isolation</code></a> and passing + it to <a href="/pkg/database/sql#DB.BeginTx"><code>DB.BeginTx</code></a>. + An error will be returned if an isolation level is selected that the driver + does not support. A read-only attribute may also be set on the transaction + by setting <a href="/pkg/database/sql/#TxOptions.ReadOnly"><code>TxOptions.ReadOnly</code></a> + to true. + </p> + <p> + Queries now expose the SQL column type information for drivers that support it. + Rows can return <a href="/pkg/database/sql#Rows.ColumnTypes"><code>ColumnTypes</code></a> + which can include SQL type information, column type lengths, and the Go type. + </p> + <p> + A <a href="/pkg/database/sql/#Rows"><code>Rows</code></a> + can now represent multiple result sets. After + <a href="/pkg/database/sql/#Rows.Next"><code>Rows.Next</code></a> returns false, + <a href="/pkg/database/sql/#Rows.NextResultSet"><code>Rows.NextResultSet</code></a> + may be called to advance to the next result set. The existing <code>Rows</code> + should continue to be used after it advances to the next result set. + </p> + <p> + <a href="/pkg/database/sql/#NamedArg"><code>NamedArg</code></a> may be used + as query arguments. The new function <a href="/pkg/database/sql/#Named"><code>Named</code></a> + helps create a <a href="/pkg/database/sql/#NamedArg"><code>NamedArg</code></a> + more succinctly. + <p> + If a driver supports the new + <a href="/pkg/database/sql/driver/#Pinger"><code>Pinger</code></a> + interface, the + <a href="/pkg/database/sql/#DB.Ping"><code>DB.Ping</code></a> + and + <a href="/pkg/database/sql/#DB.PingContext"><code>DB.PingContext</code></a> + methods will use that interface to check whether a + database connection is still valid. + </p> + <p> + The new <code>Context</code> query methods work for all drivers, but + <code>Context</code> cancelation is not responsive unless the driver has been + updated to use them. The other features require driver support in + <a href="/pkg/database/sql/driver"><code>database/sql/driver</code></a>. + Driver authors should review the new interfaces. Users of existing + driver should review the driver documentation to see what + it supports and any system specific documentation on each feature. + </p> + </dd> +</dl> + +<dl id="debug_pe"><dt><a href="/pkg/debug/pe/">debug/pe</a></dt> + <dd> + <p> <!-- CL 22720, CL 27212, CL 22181, CL 22332, CL 22336, Issue 15345 --> + The package has been extended and is now used by + <a href="/cmd/link/">the Go linker</a> to read <code>gcc</code>-generated object files. + The new + <a href="/pkg/debug/pe/#File.StringTable"><code>File.StringTable</code></a> + and + <a href="/pkg/debug/pe/#Section.Relocs"><code>Section.Relocs</code></a> + fields provide access to the COFF string table and COFF relocations. + The new + <a href="/pkg/debug/pe/#File.COFFSymbols"><code>File.COFFSymbols</code></a> + allows low-level access to the COFF symbol table. + </p> + </dd> +</dl> + +<dl id="encoding_base64"><dt><a href="/pkg/encoding/base64/">encoding/base64</a></dt> + <dd> + <p> <!-- CL 24964 --> + The new + <a href="/pkg/encoding/base64/#Encoding.Strict"><code>Encoding.Strict</code></a> + method returns an <code>Encoding</code> that causes the decoder + to return an error when the trailing padding bits are not zero. + </p> + </dd> +</dl> + +<dl id="encoding_binary"><dt><a href="/pkg/encoding/binary/">encoding/binary</a></dt> + <dd> + <p> <!-- CL 28514 --> + <a href="/pkg/encoding/binary/#Read"><code>Read</code></a> + and + <a href="/pkg/encoding/binary/#Write"><code>Write</code></a> + now support booleans. + </p> + </dd> +</dl> + +<dl id="encoding_json"><dt><a href="/pkg/encoding/json/">encoding/json</a></dt> + <dd> + + <p> <!-- CL 18692 --> + <a href="/pkg/encoding/json/#UnmarshalTypeError"><code>UnmarshalTypeError</code></a> + now includes the struct and field name. + </p> + + <p> <!-- CL 31932 --> + A nil <a href="/pkg/encoding/json/#Marshaler"><code>Marshaler</code></a> + now marshals as a JSON <code>null</code> value. + </p> + + <p> <!-- CL 21811 --> + A <a href="/pkg/encoding/json/#RawMessage"><code>RawMessage</code></a> value now + marshals the same as its pointer type. + </p> + + <p> <!-- CL 30371 --> + <a href="/pkg/encoding/json/#Marshal"><code>Marshal</code></a> + encodes floating-point numbers using the same format as in ES6, + preferring decimal (not exponential) notation for a wider range of values. + In particular, all floating-point integers up to 2<sup>64</sup> format the + same as the equivalent <code>int64</code> representation. + </p> + + <p> <!-- CL 30944 --> + In previous versions of Go, unmarshaling a JSON <code>null</code> into an + <a href="/pkg/encoding/json/#Unmarshaler"><code>Unmarshaler</code></a> + was considered a no-op; now the <code>Unmarshaler</code>'s + <code>UnmarshalJSON</code> method is called with the JSON literal + <code>null</code> and can define the semantics of that case. + </p> + + </dd> +</dl> + +<dl id="encoding_pem"><dt><a href="/pkg/encoding/pem/">encoding/pem</a></dt> + <dd> + <p> <!-- CL 27391 --> + <a href="/pkg/encoding/pem/#Decode"><code>Decode</code></a> + is now strict about the format of the ending line. + </p> + </dd> +</dl> + +<dl id="encoding_xml"><dt><a href="/pkg/encoding/xml/">encoding/xml</a></dt> + <dd> + <p> <!-- CL 30946 --> + <a href="/pkg/encoding/xml/#Unmarshal"><code>Unmarshal</code></a> + now has wildcard support for collecting all attributes using + the new <code>",any,attr"</code> struct tag. + </p> + </dd> +</dl> + +<dl id="expvar"><dt><a href="/pkg/expvar/">expvar</a></dt> + <dd> + <p> <!-- CL 30917 --> + The new methods + <a href="/pkg/expvar/#Int.Value"><code>Int.Value</code></a>, + <a href="/pkg/expvar/#String.Value"><code>String.Value</code></a>, + <a href="/pkg/expvar/#Float.Value"><code>Float.Value</code></a>, and + <a href="/pkg/expvar/#Func.Value"><code>Func.Value</code></a> + report the current value of an exported variable. + </p> + + <p> <!-- CL 24722 --> + The new + function <a href="/pkg/expvar/#Handler"><code>Handler</code></a> + returns the package's HTTP handler, to enable installing it in + non-standard locations. + </p> + </dd> +</dl> + +<dl id="fmt"><dt><a href="/pkg/fmt/">fmt</a></dt> + <dd> + <p><!-- CL 30611 --> + <a href="/pkg/fmt/#Scanf"><code>Scanf</code></a>, + <a href="/pkg/fmt/#Fscanf"><code>Fscanf</code></a>, and + <a href="/pkg/fmt/#Sscanf"><code>Sscanf</code></a> now + handle spaces differently and more consistently than + previous releases. See the + <a href="/pkg/fmt/#hdr-Scanning">scanning documentation</a> + for details. + </p> + </dd> +</dl> + +<dl id="go_doc"><dt><a href="/pkg/go/doc/">go/doc</a></dt> + <dd> + <p><!-- CL 29870 --> + The new <a href="/pkg/go/doc/#IsPredeclared"><code>IsPredeclared</code></a> + function reports whether a string is a predeclared identifier. + </p> + </dd> +</dl> + +<dl id="go_types"><dt><a href="/pkg/go/types/">go/types</a></dt> + <dd> + <p><!-- CL 30715 --> + The new function + <a href="/pkg/go/types/#Default"><code>Default</code></a> + returns the default "typed" type for an "untyped" type. + </p> + + <p><!-- CL 31939 --> + The alignment of <code>complex64</code> now matches + the <a href="/cmd/compile/">Go compiler</a>. + </p> + </dd> +</dl> + +<dl id="html_template"><dt><a href="/pkg/html/template/">html/template</a></dt> + <dd> + <p><!-- CL 14336 --> + The package now validates + the <code>"type"</code> attribute on + a <code><script></code> tag. + </p> + </dd> +</dl> + +<dl id="image_png"><dt><a href="/pkg/image/png/">image/png</a></dt> + <dd> + <p> <!-- CL 32143, CL 32140 --> + <a href="/pkg/image/png/#Decode"><code>Decode</code></a> + (and <code>DecodeConfig</code>) + now supports True Color and grayscale transparency. + </p> + <p> <!-- CL 29872 --> + <a href="/pkg/image/png/#Encoder"><code>Encoder</code></a> + is now faster and creates smaller output + when encoding paletted images. + </p> + </dd> +</dl> + +<dl id="math_big"><dt><a href="/pkg/math/big/">math/big</a></dt> + <dd> + <p><!-- CL 30706 --> + The new method + <a href="/pkg/math/big/#Int.Sqrt"><code>Int.Sqrt</code></a> + calculates ⌊√x⌋. + </p> + + <p> + The new method + <a href="/pkg/math/big/#Float.Scan"><code>Float.Scan</code></a> + is a support routine for + <a href="/pkg/fmt/#Scanner"><code>fmt.Scanner</code></a>. + </p> + + <p> + <a href="/pkg/math/big/#Int.ModInverse"><code>Int.ModInverse</code></a> + now supports negative numbers. + </p> + + </dd> +</dl> + +<dl id="math_rand"><dt><a href="/pkg/math/rand/">math/rand</a></dt> + <dd> + + <p><!-- CL 27253, CL 33456 --> + The new <a href="/pkg/math/rand/#Rand.Uint64"><code>Rand.Uint64</code></a> + method returns <code>uint64</code> values. The + new <a href="/pkg/math/rand/#Source64"><code>Source64</code></a> + interface describes sources capable of generating such values + directly; otherwise the <code>Rand.Uint64</code> method + constructs a <code>uint64</code> from two calls + to <a href="/pkg/math/rand/#Source"><code>Source</code></a>'s + <code>Int63</code> method. + </p> + + </dd> +</dl> + +<dl id="mime"><dt><a href="/pkg/mime/">mime</a></dt> + <dd> + <p> <!-- CL 32175 --> + <a href="/pkg/mime/#ParseMediaType"><code>ParseMediaType</code></a> + now preserves unnecessary backslash escapes as literals, + in order to support MSIE. + When MSIE sends a full file path (in “intranet mode”), it does not + escape backslashes: “<code>C:\dev\go\foo.txt</code>”, not + “<code>C:\\dev\\go\\foo.txt</code>”. + If we see an unnecessary backslash escape, we now assume it is from MSIE + and intended as a literal backslash. + No known MIME generators emit unnecessary backslash escapes + for simple token characters like numbers and letters. + </p> + </dd> +</dl> + +<dl id="mime_quotedprintable"><dt><a href="/pkg/mime/quotedprintable/">mime/quotedprintable</a></dt> + <dd> + + <p> + The + <a href="/pkg/mime/quotedprintable/#Reader"><code>Reader</code></a>'s + parsing has been relaxed in two ways to accept + more input seen in the wild. + + <!-- CL 32174 --> + First, it accepts an equals sign (<code>=</code>) not followed + by two hex digits as a literal equal sign. + + <!-- CL 27530 --> + Second, it silently ignores a trailing equals sign at the end of + an encoded input. + </p> + + </dd> +</dl> + +<dl id="net"><dt><a href="/pkg/net/">net</a></dt> + <dd> + + <p><!-- CL 30164, CL 33473 --> + The <a href="/pkg/net/#Conn"><code>Conn</code></a> documentation + has been updated to clarify expectations of an interface + implementation. Updates in the <code>net/http</code> packages + depend on implementations obeying the documentation. + </p> + <p><i>Updating:</i> implementations of the <code>Conn</code> interface should verify + they implement the documented semantics. The + <a href="https://godoc.org/golang.org/x/net/nettest">golang.org/x/net/nettest</a> + package will exercise a <code>Conn</code> and validate it behaves properly. + </p> + + <p><!-- CL 32099 --> + The new method + <a href="/pkg/net/#UnixListener.SetUnlinkOnClose"><code>UnixListener.SetUnlinkOnClose</code></a> + sets whether the underlying socket file should be removed from the file system when + the listener is closed. + </p> + + <p><!-- CL 29951 --> + The new <a href="/pkg/net/#Buffers"><code>Buffers</code></a> type permits + writing to the network more efficiently from multiple discontiguous buffers + in memory. On certain machines, for certain types of connections, + this is optimized into an OS-specific batch write operation (such as <code>writev</code>). + </p> + + <p><!-- CL 29440 --> + The new <a href="/pkg/net/#Resolver"><code>Resolver</code></a> looks up names and numbers + and supports <a href="/pkg/context/#Context"><code>context.Context</code></a>. + The <a href="/pkg/net/#Dialer"><code>Dialer</code></a> now has an optional + <a href="/pkg/net/#Dialer.Resolver"><code>Resolver</code> field</a>. + </p> + + <p><!-- CL 29892 --> + <a href="/pkg/net/#Interfaces"><code>Interfaces</code></a> is now supported on Solaris. + </p> + + <p><!-- CL 29233, CL 24901 --> + The Go DNS resolver now supports <code>resolv.conf</code>'s “<code>rotate</code>” + and “<code>option</code> <code>ndots:0</code>” options. The “<code>ndots</code>” option is + now respected in the same way as <code>libresolve</code>. + </p> + + </dd> +</dl> + +<dl id="net_http"><dt><a href="/pkg/net/http/">net/http</a></dt> + <dd> + + <p>Server changes:</p> + <ul> + <li>The server now supports graceful shutdown support, <a href="#http_shutdown">mentioned above</a>.</li> + + <li> <!-- CL 32024 --> + The <a href="/pkg/net/http/#Server"><code>Server</code></a> + adds configuration options + <code>ReadHeaderTimeout</code> and <code>IdleTimeout</code> + and documents <code>WriteTimeout</code>. + </li> + + <li> <!-- CL 32014 --> + <a href="/pkg/net/http/#FileServer"><code>FileServer</code></a> + and + <a href="/pkg/net/http/#ServeContent"><code>ServeContent</code></a> + now support HTTP <code>If-Match</code> conditional requests, + in addition to the previous <code>If-None-Match</code> + support for ETags properly formatted according to RFC 7232, section 2.3. + </li> + </ul> + + <p> + There are several additions to what a server's <code>Handler</code> can do: + </p> + + <ul> + <li><!-- CL 31173 --> + The <a href="/pkg/context/#Context"><code>Context</code></a> + returned + by <a href="/pkg/net/http/#Request.Context"><code>Request.Context</code></a> + is canceled if the underlying <code>net.Conn</code> + closes. For instance, if the user closes their browser in the + middle of a slow request, the <code>Handler</code> can now + detect that the user is gone. This complements the + existing <a href="/pkg/net/http/#CloseNotifier"><code>CloseNotifier</code></a> + support. This functionality requires that the underlying + <a href="/pkg/net/#Conn"><code>net.Conn</code></a> implements + <a href="#net">recently clarified interface documentation</a>. + </li> + + <li><!-- CL 32479 --> + To serve trailers produced after the header has already been written, + see the new + <a href="/pkg/net/http/#TrailerPrefix"><code>TrailerPrefix</code></a> + mechanism. + </li> + + <li><!-- CL 33099 --> + A <code>Handler</code> can now abort a response by panicking + with the error + <a href="/pkg/net/http/#ErrAbortHandler"><code>ErrAbortHandler</code></a>. + </li> + + <li><!-- CL 30812 --> + A <code>Write</code> of zero bytes to a + <a href="/pkg/net/http/#ResponseWriter"><code>ResponseWriter</code></a> + is now defined as a + way to test whether a <code>ResponseWriter</code> has been hijacked: + if so, the <code>Write</code> returns + <a href="/pkg/net/http/#ErrHijacked"><code>ErrHijacked</code></a> + without printing an error + to the server's error log. + </li> + + </ul> + + <p>Client & Transport changes:</p> + <ul> + <li><!-- CL 28930, CL 31435 --> + The <a href="/pkg/net/http/#Client"><code>Client</code></a> + now copies most request headers on redirect. See + <a href="/pkg/net/http/#Client">the documentation</a> + on the <code>Client</code> type for details. + </li> + + <li><!-- CL 29072 --> + The <a href="/pkg/net/http/#Transport"><code>Transport</code></a> + now supports international domain names. Consequently, so do + <a href="/pkg/net/http/#Get">Get</a> and other helpers. + </li> + + <li><!-- CL 31733, CL 29852 --> + The <code>Client</code> now supports 301, 307, and 308 redirects. + + For example, <code>Client.Post</code> now follows 301 + redirects, converting them to <code>GET</code> requests + without bodies, like it did for 302 and 303 redirect responses + previously. + + The <code>Client</code> now also follows 307 and 308 + redirects, preserving the original request method and body, if + any. If the redirect requires resending the request body, the + request must have the new + <a href="/pkg/net/http/#Request"><code>Request.GetBody</code></a> + field defined. + <a href="/pkg/net/http/#NewRequest"><code>NewRequest</code></a> + sets <code>Request.GetBody</code> automatically for common + body types. + </li> + + <li><!-- CL 32482 --> + The <code>Transport</code> now rejects requests for URLs with + ports containing non-digit characters. + </li> + + <li><!-- CL 27117 --> + The <code>Transport</code> will now retry non-idempotent + requests if no bytes were written before a network failure + and the request has no body. + </li> + + <li><!-- CL 32481 --> + The + new <a href="/pkg/net/http/#Transport"><code>Transport.ProxyConnectHeader</code></a> + allows configuration of header values to send to a proxy + during a <code>CONNECT</code> request. + </li> + + <li> <!-- CL 28077 --> + The <a href="/pkg/net/http/#DefaultTransport"><code>DefaultTransport.Dialer</code></a> + now enables <code>DualStack</code> ("<a href="https://tools.ietf.org/html/rfc6555">Happy Eyeballs</a>") support, + allowing the use of IPv4 as a backup if it looks like IPv6 might be + failing. + </li> + + <li> <!-- CL 31726 --> + The <a href="/pkg/net/http/#Transport"><code>Transport</code></a> + no longer reads a byte of a non-nil + <a href="/pkg/net/http/#Request.Body"><code>Request.Body</code></a> + when the + <a href="/pkg/net/http/#Request.ContentLength"><code>Request.ContentLength</code></a> + is zero to determine whether the <code>ContentLength</code> + is actually zero or just undefined. + To explicitly signal that a body has zero length, + either set it to <code>nil</code>, or set it to the new value + <a href="/pkg/net/http/#NoBody"><code>NoBody</code></a>. + The new <code>NoBody</code> value is intended for use by <code>Request</code> + constructor functions; it is used by + <a href="/pkg/net/http/#NewRequest"><code>NewRequest</code></a>. + </li> + </ul> + + </dd> +</dl> + +<dl id="net_http_httptrace"><dt><a href="/pkg/net/http/httptrace/">net/http/httptrace</a></dt> + <dd> + <p> <!-- CL 30359 --> + There is now support for tracing a client request's TLS handshakes with + the new + <a href="/pkg/net/http/httptrace/#ClientTrace.TLSHandshakeStart"><code>ClientTrace.TLSHandshakeStart</code></a> + and + <a href="/pkg/net/http/httptrace/#ClientTrace.TLSHandshakeDone"><code>ClientTrace.TLSHandshakeDone</code></a>. + </p> + </dd> +</dl> + +<dl id="net_http_httputil"><dt><a href="/pkg/net/http/httputil/">net/http/httputil</a></dt> + <dd> + <p> <!-- CL 32356 --> + The <a href="/pkg/net/http/httputil/#ReverseProxy"><code>ReverseProxy</code></a> + has a new optional hook, + <a href="/pkg/net/http/httputil/#ReverseProxy.ModifyResponse"><code>ModifyResponse</code></a>, + for modifying the response from the back end before proxying it to the client. + </p> + + </dd> +</dl> + +<dl id="net_mail"><dt><a href="/pkg/net/mail/">net/mail</a></dt> + <dd> + + <p> <!-- CL 32176 --> + Empty quoted strings are once again allowed in the name part of + an address. That is, Go 1.4 and earlier accepted + <code>""</code> <code><gopher@example.com></code>, + but Go 1.5 introduced a bug that rejected this address. + The address is recognized again. + </p> + + <p> <!-- CL 31581 --> + The + <a href="/pkg/net/mail/#Header.Date"><code>Header.Date</code></a> + method has always provided a way to parse + the <code>Date:</code> header. + A new function + <a href="/pkg/net/mail/#ParseDate"><code>ParseDate</code></a> + allows parsing dates found in other + header lines, such as the <code>Resent-Date:</code> header. + </p> + + </dd> +</dl> + +<dl id="net_smtp"><dt><a href="/pkg/net/smtp/">net/smtp</a></dt> + <dd> + + <p> <!-- CL 33143 --> + If an implementation of the + <a href="/pkg/net/smtp/#Auth"><code>Auth.Start</code></a> + method returns an empty <code>toServer</code> value, + the package no longer sends + trailing whitespace in the SMTP <code>AUTH</code> command, + which some servers rejected. + </p> + + </dd> +</dl> + +<dl id="net_url"><dt><a href="/pkg/net/url/">net/url</a></dt> + <dd> + + <p> <!-- CL 31322 --> + The new functions + <a href="/pkg/net/url/#PathEscape"><code>PathEscape</code></a> + and + <a href="/pkg/net/url/#PathUnescape"><code>PathUnescape</code></a> + are similar to the query escaping and unescaping functions but + for path elements. + </p> + + <p> <!-- CL 28933 --> + The new methods + <a href="/pkg/net/url/#URL.Hostname"><code>URL.Hostname</code></a> + and + <a href="/pkg/net/url/#URL.Port"><code>URL.Port</code></a> + return the hostname and port fields of a URL, + correctly handling the case where the port may not be present. + </p> + + <p> <!-- CL 28343 --> + The existing method + <a href="/pkg/net/url/#URL.ResolveReference"><code>URL.ResolveReference</code></a> + now properly handles paths with escaped bytes without losing + the escaping. + </p> + + <p> <!-- CL 31467 --> + The <code>URL</code> type now implements + <a href="/pkg/encoding/#BinaryMarshaler"><code>encoding.BinaryMarshaler</code></a> and + <a href="/pkg/encoding/#BinaryUnmarshaler"><code>encoding.BinaryUnmarshaler</code></a>, + making it possible to process URLs in <a href="/pkg/encoding/gob/">gob data</a>. + </p> + + <p> <!-- CL 29610, CL 31582 --> + Following RFC 3986, + <a href="/pkg/net/url/#Parse"><code>Parse</code></a> + now rejects URLs like <code>this_that:other/thing</code> instead of + interpreting them as relative paths (<code>this_that</code> is not a valid scheme). + To force interpretation as a relative path, + such URLs should be prefixed with “<code>./</code>”. + The <code>URL.String</code> method now inserts this prefix as needed. + </p> + + </dd> +</dl> + +<dl id="os"><dt><a href="/pkg/os/">os</a></dt> + <dd> + <p> <!-- CL 16551 --> + The new function + <a href="/pkg/os/#Executable"><code>Executable</code></a> returns + the path name of the running executable. + </p> + + <p> <!-- CL 30614 --> + An attempt to call a method on + an <a href="/pkg/os/#File"><code>os.File</code></a> that has + already been closed will now return the new error + value <a href="/pkg/os/#ErrClosed"><code>os.ErrClosed</code></a>. + Previously it returned a system-specific error such + as <code>syscall.EBADF</code>. + </p> + + <p> <!-- CL 31358 --> + On Unix systems, <a href="/pkg/os/#Rename"><code>os.Rename</code></a> + will now return an error when used to rename a directory to an + existing empty directory. + Previously it would fail when renaming to a non-empty directory + but succeed when renaming to an empty directory. + This makes the behavior on Unix correspond to that of other systems. + </p> + + <p> <!-- CL 32451 --> + On Windows, long absolute paths are now transparently converted to + extended-length paths (paths that start with “<code>\\?\</code>”). + This permits the package to work with files whose path names are + longer than 260 characters. + </p> + + <p> <!-- CL 29753 --> + On Windows, <a href="/pkg/os/#IsExist"><code>os.IsExist</code></a> + will now return <code>true</code> for the system + error <code>ERROR_DIR_NOT_EMPTY</code>. + This roughly corresponds to the existing handling of the Unix + error <code>ENOTEMPTY</code>. + </p> + + <p> <!-- CL 32152 --> + On Plan 9, files that are not served by <code>#M</code> will now + have <a href="/pkg/os/#ModeDevice"><code>ModeDevice</code></a> set in + the value returned + by <a href="/pkg/os/#FileInfo"><code>FileInfo.Mode</code></a>. + </p> + </dd> +</dl> + +<dl id="path_filepath"><dt><a href="/pkg/path/filepath/">path/filepath</a></dt> + <dd> + <p> + A number of bugs and corner cases on Windows were fixed: + <a href="/pkg/path/filepath/#Abs"><code>Abs</code></a> now calls <code>Clean</code> as documented, + <a href="/pkg/path/filepath/#Glob"><code>Glob</code></a> now matches + “<code>\\?\c:\*</code>”, + <a href="/pkg/path/filepath/#EvalSymlinks"><code>EvalSymlinks</code></a> now + correctly handles “<code>C:.</code>”, and + <a href="/pkg/path/filepath/#Clean"><code>Clean</code></a> now properly + handles a leading “<code>..</code>” in the path. + </p> + </dd> +</dl> + +<dl id="reflect"><dt><a href="/pkg/reflect/">reflect</a></dt> + <dd> + <p> <!-- CL 30088 --> + The new function + <a href="/pkg/reflect/#Swapper"><code>Swapper</code></a> was + added to support <a href="#sortslice"><code>sort.Slice</code></a>. + </p> + </dd> +</dl> + +<dl id="strconv"><dt><a href="/pkg/strconv/">strconv</a></dt> + <dd> + <p> <!-- CL 31210 --> + The <a href="/pkg/strconv/#Unquote"><code>Unquote</code></a> + function now strips carriage returns (<code>\r</code>) in + backquoted raw strings, following the + <a href="/ref/spec#String_literals">Go language semantics</a>. + </p> + </dd> +</dl> + +<dl id="syscall"><dt><a href="/pkg/syscall/">syscall</a></dt> + <dd> + <p> <!-- CL 25050, CL 25022 --> + The <a href="/pkg/syscall/#Getpagesize"><code>Getpagesize</code></a> + now returns the system's size, rather than a constant value. + Previously it always returned 4KB. + </p> + + <p> <!-- CL 31446 --> + The signature + of <a href="/pkg/syscall/#Utimes"><code>Utimes</code></a> has + changed on Solaris to match all the other Unix systems' + signature. Portable code should continue to use + <a href="/pkg/os/#Chtimes"><code>os.Chtimes</code></a> instead. + </p> + + <p> <!-- CL 32319 --> + The <code>X__cmsg_data</code> field has been removed from + <a href="/pkg/syscall/#Cmsghdr"><code>Cmsghdr</code></a>. + </p> + </dd> +</dl> + +<dl id="text_template"><dt><a href="/pkg/text/template/">text/template</a></dt> + <dd> + <p> <!-- CL 31462 --> + <a href="/pkg/text/template/#Template.Execute"><code>Template.Execute</code></a> + can now take a + <a href="/pkg/reflect/#Value"><code>reflect.Value</code></a> as its data + argument, and + <a href="/pkg/text/template/#FuncMap"><code>FuncMap</code></a> + functions can also accept and return <code>reflect.Value</code>. + </p> + + </dd> +</dl> + +<dl id="time"><dt><a href="/pkg/time/">time</a></dt> + <dd> + + <p> <!-- CL 20118 --> The new function + <a href="/pkg/time/#Until"><code>Until</code></a> complements + the analogous <code>Since</code> function. + </p> + + <p> <!-- CL 29338 --> + <a href="/pkg/time/#ParseDuration"><code>ParseDuration</code></a> + now accepts long fractional parts. + </p> + + <p> <!-- CL 33429 --> + <a href="/pkg/time/#Parse"><code>Parse</code></a> + now rejects dates before the start of a month, such as June 0; + it already rejected dates beyond the end of the month, such as + June 31 and July 32. + </p> + + <p> <!-- CL 33029 --> <!-- CL 34816 --> + The <code>tzdata</code> database has been updated to version + 2016j for systems that don't already have a local time zone + database. + </p> + + <p> + </dd> +</dl> + +<dl id="testing"><dt><a href="/pkg/testing/">testing</a></dt> + <dd> + <p><!-- CL 29970 --> + The new method + <a href="/pkg/testing/#T.Name"><code>T.Name</code></a> + (and <code>B.Name</code>) returns the name of the current + test or benchmark. + </p> + + <p><!-- CL 32483 --> + The new function + <a href="/pkg/testing/#CoverMode"><code>CoverMode</code></a> + reports the test coverage mode. + </p> + + <p><!-- CL 32615 --> + Tests and benchmarks are now marked as failed if the race + detector is enabled and a data race occurs during execution. + Previously, individual test cases would appear to pass, + and only the overall execution of the test binary would fail. + </p> + + <p><!-- CL 32455 --> + The signature of the + <a href="/pkg/testing/#MainStart"><code>MainStart</code></a> + function has changed, as allowed by the documentation. It is an + internal detail and not part of the Go 1 compatibility promise. + If you're not calling <code>MainStart</code> directly but see + errors, that likely means you set the + normally-empty <code>GOROOT</code> environment variable and it + doesn't match the version of your <code>go</code> command's binary. + </p> + + </dd> +</dl> + +<dl id="unicode"><dt><a href="/pkg/unicode/">unicode</a></dt> + <dd> + <p><!-- CL 30935 --> + <a href="/pkg/unicode/#SimpleFold"><code>SimpleFold</code></a> + now returns its argument unchanged if the provided input was an invalid rune. + Previously, the implementation failed with an index bounds check panic. + </p> + </dd> +</dl> |