[dev.typeparams] all: merge master (16e82be) into dev.typeparams

Merge List:

+ 2021-06-21 16e82be454 runtime: fix crash during VDSO calls on PowerPC
+ 2021-06-21 2e542c3c06 runtime/pprof: deflake TestMorestack more
+ 2021-06-21 ced0fdbad0 doc/go1.17: note deprecation of 'go get' for installing commands
+ 2021-06-21 7a5e7047a4 doc/go1.17: add Go 1.18 pre-announcements
+ 2021-06-21 85a2e24afd doc/go1.17: add security-related release notes
+ 2021-06-21 1de332996c doc/go1.17: document go/parser.SkipObjectResolution
+ 2021-06-21 117ebe0f52 cmd/go: do not require the module cache to exist for 'go mod edit'
+ 2021-06-20 460900a7b5 os/signal: test with a significantly longer fatal timeout
+ 2021-06-19 b73cc4b02b database/sql: do not rely on timeout for deadlock test
+ 2021-06-18 86743e7d86 image: add RGBA64Image interface
+ 2021-06-18 9401172166 runtime: clarify Frames.Next documentation
+ 2021-06-18 57aaa19aae runtime: disable CPU profiling before removing the SIGPROF handler
+ 2021-06-18 6f22d2c682 doc/go1.17: fix typo
+ 2021-06-17 45f251ad6c cmd/pprof,runtime/pprof: disable test on more broken platforms
+ 2021-06-17 ed834853ad cmd/go: replace a TODO with an explanatory comment
+ 2021-06-17 4dede02550 cmd/pprof: make ObjAddr a no-op
+ 2021-06-17 97cee43c93 testing: drop unusual characters from TempDir directory name
+ 2021-06-17 b0355a3e72 time: fix receiver for Time.IsDST method
+ 2021-06-17 881b6ea7ba doc/go1.17: fix redundant space
+ 2021-06-16 0e67ce3d28 cmd/go: in lazy modules, add transitive imports for 'go get' arguments
+ 2021-06-16 6ea2af0890 cmd/go: add a regression test for #45979
+ 2021-06-16 a294e4e798 math/rand: mention half-open intervals explicitly
+ 2021-06-16 a6a853f94c cmd/asm: restore supporting of *1 scaling on ARM64

Change-Id: Ifdcb817fd44b4fa9c477042b41da55d1d769b016

api/go1.17.txt

@@ -28,6 +28,38 @@ pkg encoding/csv, method (*Reader) FieldPos(int) (int, int)
 pkg go/build, type Context struct, ToolTags []string
 pkg go/parser, const SkipObjectResolution = 64
 pkg go/parser, const SkipObjectResolution Mode
+pkg image, method (*Alpha) RGBA64At(int, int) color.RGBA64
+pkg image, method (*Alpha) SetRGBA64(int, int, color.RGBA64)
+pkg image, method (*Alpha16) RGBA64At(int, int) color.RGBA64
+pkg image, method (*Alpha16) SetRGBA64(int, int, color.RGBA64)
+pkg image, method (*CMYK) RGBA64At(int, int) color.RGBA64
+pkg image, method (*CMYK) SetRGBA64(int, int, color.RGBA64)
+pkg image, method (*Gray) RGBA64At(int, int) color.RGBA64
+pkg image, method (*Gray) SetRGBA64(int, int, color.RGBA64)
+pkg image, method (*Gray16) RGBA64At(int, int) color.RGBA64
+pkg image, method (*Gray16) SetRGBA64(int, int, color.RGBA64)
+pkg image, method (*NRGBA) RGBA64At(int, int) color.RGBA64
+pkg image, method (*NRGBA) SetRGBA64(int, int, color.RGBA64)
+pkg image, method (*NRGBA64) RGBA64At(int, int) color.RGBA64
+pkg image, method (*NRGBA64) SetRGBA64(int, int, color.RGBA64)
+pkg image, method (*NYCbCrA) RGBA64At(int, int) color.RGBA64
+pkg image, method (*Paletted) RGBA64At(int, int) color.RGBA64
+pkg image, method (*Paletted) SetRGBA64(int, int, color.RGBA64)
+pkg image, method (*RGBA) RGBA64At(int, int) color.RGBA64
+pkg image, method (*RGBA) SetRGBA64(int, int, color.RGBA64)
+pkg image, method (*YCbCr) RGBA64At(int, int) color.RGBA64
+pkg image, type RGBA64Image interface { At, Bounds, ColorModel, RGBA64At }
+pkg image, type RGBA64Image interface, At(int, int) color.Color
+pkg image, type RGBA64Image interface, Bounds() Rectangle
+pkg image, type RGBA64Image interface, ColorModel() color.Model
+pkg image, type RGBA64Image interface, RGBA64At(int, int) color.RGBA64
+pkg image/draw, type RGBA64Image interface { At, Bounds, ColorModel, RGBA64At, Set, SetRGBA64 }
+pkg image/draw, type RGBA64Image interface, At(int, int) color.Color
+pkg image/draw, type RGBA64Image interface, Bounds() image.Rectangle
+pkg image/draw, type RGBA64Image interface, ColorModel() color.Model
+pkg image/draw, type RGBA64Image interface, RGBA64At(int, int) color.RGBA64
+pkg image/draw, type RGBA64Image interface, Set(int, int, color.Color)
+pkg image/draw, type RGBA64Image interface, SetRGBA64(int, int, color.RGBA64)
 pkg io/fs, func FileInfoToDirEntry(FileInfo) DirEntry
 pkg math, const MaxFloat64 = 1.79769e+308  // 179769313486231570814527423731704356798070567525844996598917476803157260780028538760589558632766878171540458953514382464234321326889464182768467546703537516986049910576551282076245490090389328944075868508455133942304583236903222948165808559332123348274797826204144723168738177180919299881250404026184124858368
 pkg math, const MaxInt = 9223372036854775807
@@ -153,7 +185,7 @@ pkg time, const Layout = "01/02 03:04:05PM '06 -0700"
 pkg time, const Layout ideal-string
 pkg time, func UnixMicro(int64) Time
 pkg time, func UnixMilli(int64) Time
-pkg time, method (*Time) IsDST() bool
 pkg time, method (Time) GoString() string
+pkg time, method (Time) IsDST() bool
 pkg time, method (Time) UnixMicro() int64
 pkg time, method (Time) UnixMilli() int64

doc/go1.17.html

@@ -162,7 +162,7 @@ Do not send CLs removing the interior tags from such phrases.
   By default, <code>go</code> <code>mod</code> <code>tidy</code> verifies that
   the selected versions of dependencies relevant to the main module are the same
   versions that would be used by the prior Go release (Go 1.16 for a module that
-  spsecifies <code>go</code> <code>1.17</code>), and preserves
+  specifies <code>go</code> <code>1.17</code>), and preserves
   the <code>go.sum</code> entries needed by that release even for dependencies
   that are not normally needed by other commands.
 </p>
@@ -214,6 +214,16 @@ Do not send CLs removing the interior tags from such phrases.
   <code>environment</code> for details.
 </p>
 
+<p><!-- golang.org/issue/43684 -->
+  <code>go</code> <code>get</code> prints a deprecation warning when installing
+  commands outside the main module (without the <code>-d</code> flag).
+  <code>go</code> <code>install</code> <code>cmd@version</code> should be used
+  instead to install a command at a specific version, using a suffix like
+  <code>@latest</code> or <code>@v1.2.3</code>. In Go 1.18, the <code>-d</code>
+  flag will always be enabled, and <code>go</code> <code>get</code> will only
+  be used to change dependencies in <code>go.mod</code>.
+</p>
+
 <h4 id="missing-go-directive"><code>go.mod</code> files missing <code>go</code> directives</h4>
 
 <p><!-- golang.org/issue/44976 -->
@@ -387,7 +397,7 @@ func Foo() bool {
   registers instead of the stack. This work is enabled for Linux, MacOS, and
   Windows on the 64-bit x86 architecture (the <code>linux/amd64</code>,
   <code>darwin/amd64</code>, <code>windows/amd64</code> ports). For a
-  representative set of Go  packages and programs, benchmarking has shown
+  representative set of Go packages and programs, benchmarking has shown
   performance improvements of about 5%, and a typical reduction in binary size
   of about 2%.
 </p>
@@ -441,6 +451,67 @@ func Foo() bool {
   <a href="/pkg/runtime/cgo#Handle">runtime/cgo.Handle</a> for more information.
 </p>
 
+<h3 id="semicolons">URL query parsing</h3>
+<!-- CL 325697, CL 326309 -->
+
+<p>
+  The <code>net/url</code> and <code>net/http</code> packages used to accept
+  <code>";"</code> (semicolon) as a setting separator in URL queries, in
+  addition to <code>"&"</code> (ampersand). Now, settings with non-percent-encoded
+  semicolons are rejected and <code>net/http</code> servers will log a warning to
+  <a href="/pkg/net/http#Server.ErrorLog"><code>Server.ErrorLog</code></a>
+  when encountering one in a request URL.
+</p>
+
+<p>
+  For example, before Go 1.17 the <a href="/pkg/net/url#URL.Query"><code>Query</code></a>
+  method of the URL <code>example?a=1;b=2&c=3</code> would have returned
+  <code>map[a:[1] b:[2] c:[3]]</code>, while now it returns <code>map[c:[3]]</code>.
+</p>
+
+<p>
+  When encountering such a query string,
+  <a href="/pkg/net/url#URL.Query"><code>URL.Query</code></a>
+  and
+  <a href="/pkg/net/http#Request.FormValue"><code>Request.FormValue</code></a>
+  ignore any settings that contain a semicolon,
+  <a href="/pkg/net/url#ParseQuery"><code>ParseQuery</code></a>
+  returns the remaining settings and an error, and
+  <a href="/pkg/net/http#Request.ParseForm"><code>Request.ParseForm</code></a>
+  and
+  <a href="/pkg/net/http#Request.ParseMultipartForm"><code>Request.ParseMultipartForm</code></a>
+  return an error but still set <code>Request</code> fields based on the
+  remaining settings.
+</p>
+
+<p>
+  <code>net/http</code> users can restore the original behavior by using the new
+  <a href="/pkg/net/http#AllowQuerySemicolons"><code>AllowQuerySemicolons</code></a>
+  handler wrapper. This will also suppress the <code>ErrorLog</code> warning.
+  Note that accepting semicolons as query separators can lead to security issues
+  if different systems interpret cache keys differently.
+  See <a href="https://golang.org/issue/25192">issue 25192</a> for more information.
+</p>
+
+<h3 id="ALPN">TLS strict ALPN</h3>
+<!-- CL 289209, CL 325432 -->
+
+<p>
+  When <a href="/pkg/crypto/tls#Config.NextProtos"><code>Config.NextProtos</code></a>
+  is set, servers now enforce that there is an overlap between the configured
+  protocols and the ALPN protocols advertised by the client, if any. If there is
+  no mutually supported protocol, the connection is closed with the
+  <code>no_application_protocol</code> alert, as required by RFC 7301. This
+  helps mitigate <a href="https://alpaca-attack.com/">the ALPACA cross-protocol attack</a>.
+</p>
+
+<p>
+  As an exception, when the value <code>"h2"</code> is included in the server's
+  <code>Config.NextProtos</code>, HTTP/1.1 clients will be allowed to connect as
+  if they didn't support ALPN.
+  See <a href="https://golang.org/issue/46310">issue 46310</a> for more information.
+</p>
+
 <h3 id="minor_library_changes">Minor changes to the library</h3>
 
 <p>
@@ -549,14 +620,6 @@ func Foo() bool {
       methods. Canceling the context after the handshake has finished has no effect.
     </p>
 
-    <p><!-- CL 289209 -->
-      When <a href="/pkg/crypto/tls#Config.NextProtos"><code>Config.NextProtos</code></a>
-      is set, servers now enforce that there is an overlap between the
-      configured protocols and the protocols advertised by the client, if any.
-      If there is no overlap the connection is closed with the
-      <code>no_application_protocol</code> alert, as required by RFC 7301.
-    </p>
-
     <p><!-- CL 314609 -->
       Cipher suite ordering is now handled entirely by the
       <code>crypto/tls</code> package. Currently, cipher suites are sorted based
@@ -576,6 +639,15 @@ func Foo() bool {
       weakness</a>. They are still enabled by default but only as a last resort,
       thanks to the cipher suite ordering change above.
     </p>
+
+    <p><!-- golang.org/issue/45428 -->
+      Beginning in the next release, Go 1.18, the
+      <a href="/pkg/crypto/tls/#Config.MinVersion"><code>Config.MinVersion</code></a>
+      for <code>crypto/tls</code> clients will default to TLS 1.2, disabling TLS 1.0
+      and TLS 1.1 by default. Applications will be able to override the change by
+      explicitly setting <code>Config.MinVersion</code>.
+      This will not affect <code>crypto/tls</code> servers.
+    </p>
   </dd>
 </dl><!-- crypto/tls -->
 
@@ -603,6 +675,14 @@ func Foo() bool {
       roots. This adds support for the new system trusted certificate store in
       FreeBSD 12.2+.
     </p>
+
+    <p><!-- golang.org/issue/41682 -->
+      Beginning in the next release, Go 1.18, <code>crypto/x509</code> will
+      reject certificates signed with the SHA-1 hash function. This doesn't
+      apply to self-signed root certificates. Practical attacks against SHA-1
+      <a href="https://shattered.io/">have been demonstrated in 2017</a> and publicly
+      trusted Certificate Authorities have not issued SHA-1 certificates since 2015.
+    </p>
   </dd>
 </dl><!-- crypto/x509 -->
 
@@ -658,6 +738,22 @@ func Foo() bool {
   </dd>
 </dl><!-- encoding/csv -->
 
+<dl id="encoding/xml"><dt><a href="/pkg/encoding/xml/">encoding/xml</a></dt>
+  <dd>
+    <p><!-- CL 277893 -->
+      When a comment appears within a
+      <a href="/pkg/encoding/xml/#Directive"><code>Directive</code></a>, it is now replaced
+      with a single space instead of being completely elided.
+    </p>
+
+    <p>
+      Invalid element or attribute names with leading, trailing, or multiple
+      colons are now stored unmodified into the
+      <a href="/pkg/encoding/xml/#Name"><code>Name.Local</code></a> field.
+    </p>
+  </dd>
+</dl><!-- encoding/xml -->
+
 <dl id="flag"><dt><a href="/pkg/flag/">flag</a></dt>
   <dd>
     <p><!-- CL 271788 -->
@@ -693,6 +789,29 @@ func Foo() bool {
   </dd>
 </dl><!-- go/format -->
 
+<dl id="go/parser"><dt><a href="/pkg/go/parser/">go/parser</a></dt>
+  <dd>
+    <p><!-- CL 306149 -->
+      The new <a href="/pkg/go/parser/#SkipObjectResolution"><code>SkipObjectResolution</code></a>
+      <code>Mode</code> value instructs the parser not to resolve identifiers to
+      their declaration. This may improve parsing speed.
+    </p>
+  </dd>
+</dl><!-- go/parser -->
+
+<dl id="image"><dt><a href="/pkg/image/">image</a></dt>
+  <dd>
+    <p><!-- CL 311129 -->
+      The concrete image types (<code>RGBA</code>, <code>Gray16</code> and so on)
+      now implement a new <a href="/pkg/image/#RGBA64Image"><code>RGBA64Image</code></a>
+      interface. Those concrete types, other than the chroma-subsampling
+      related <code>YCbCr</code> and <code>NYCbCrA</code>, also now implement
+      <a href="/pkg/image/draw/#RGBA64Image"><code>draw.RGBA64Image</code></a>, a
+      new interface in the <code>image/draw</code> package.
+    </p>
+  </dd>
+</dl><!-- image -->
+
 <dl id="io/fs"><dt><a href="/pkg/io/fs/">io/fs</a></dt>
   <dd>
     <p><!-- CL 293649 -->
@@ -721,6 +840,20 @@ func Foo() bool {
   </dd>
 </dl><!-- mime -->
 
+<dl id="mime/multipart"><dt><a href="/pkg/mime/multipart/">mime/multipart</a></dt>
+  <dd>
+    <p><!-- CL 313809 -->
+      <a href="/pkg/mime/multipart/#Part.FileName"><code>Part.FileName</code></a>
+      now applies
+      <a href="/pkg/path/filepath/#Base"><code>filepath.Base</code></a> to the
+      return value. This mitigates potential path traversal vulnerabilities in
+      applications that accept multipart messages, such as <code>net/http</code>
+      servers that call
+      <a href="/pkg/net/http/#Request.FormFile"><code>Request.FormFile</code></a>.
+    </p>
+  </dd>
+</dl><!-- mime/multipart -->
+
 <dl id="net"><dt><a href="/pkg/net/">net</a></dt>
   <dd>
     <p><!-- CL 272668 -->
@@ -740,7 +873,7 @@ func Foo() bool {
       the <a href="/pkg/net/#Error"><code>net.Error</code></a> interface.
     </p>
 
-    <p><!-- CL325829 -->
+    <p><!-- CL 325829 -->
       The <a href="/pkg/net/#ParseIP"><code>ParseIP</code></a> and <a href="/pkg/net/#ParseCIDR"><code>ParseCIDR</code></a>
       functions now reject IPv4 addresses which contain decimal components with leading zeros.
 
@@ -771,6 +904,29 @@ func Foo() bool {
       The <a href="/pkg/net/http/#ReadRequest"><code>ReadRequest</code></a> function
       now returns an error when the request has multiple Host headers.
     </p>
+
+    <p><!-- CL 313950 -->
+      When producing a redirect to the cleaned version of a URL,
+      <a href="/pkg/net/http/#ServeMux"><code>ServeMux</code></a> now always
+      uses relative URLs in the <code>Location</code> header. Previously it
+      would echo the full URL of the request, which could lead to unintended
+      redirects if the client could be made to send an absolute request URL.
+    </p>
+
+    <p><!-- CL 308009, CL 313489 -->
+      When interpreting certain HTTP headers handled by <code>net/http</code>,
+      non-ASCII characters are now ignored or rejected.
+    </p>
+
+    <p><!-- CL 325697 -->
+      If
+      <a href="/pkg/net/http/#Request.ParseForm"><code>Request.ParseForm</code></a>
+      returns an error when called by
+      <a href="/pkg/net/http/#Request.ParseMultipartForm"><code>Request.ParseMultipartForm</code></a>,
+      the latter now continues populating
+      <a href="/pkg/net/http/#Request.MultipartForm"><code>Request.MultipartForm</code></a>
+      before returning it.
+    </p>
   </dd>
 </dl><!-- net/http -->
 

src/cmd/asm/internal/asm/parse.go

@@ -1003,7 +1003,8 @@ func (p *Parser) registerIndirect(a *obj.Addr, prefix rune) {
 				p.errorf("unimplemented two-register form")
 			}
 			a.Index = r1
-			if scale != 0 && p.arch.Family == sys.ARM64 {
+			if scale != 0 && scale != 1 && p.arch.Family == sys.ARM64 {
+				// Support (R1)(R2) (no scaling) and (R1)(R2*1).
 				p.errorf("arm64 doesn't support scaled register format")
 			} else {
 				a.Scale = int16(scale)

src/cmd/asm/internal/asm/testdata/arm64.s

@@ -547,6 +547,7 @@ TEXT	foo(SB), DUPOK|NOSPLIT, $-8
 // shifted or extended register offset.
 	MOVD	(R2)(R6.SXTW), R4               // 44c866f8
 	MOVD	(R3)(R6), R5                    // 656866f8
+	MOVD	(R3)(R6*1), R5                  // 656866f8
 	MOVD	(R2)(R6), R4                    // 446866f8
 	MOVWU	(R19)(R20<<2), R20              // 747a74b8
 	MOVD	(R2)(R6<<3), R4                 // 447866f8
@@ -579,6 +580,7 @@ TEXT	foo(SB), DUPOK|NOSPLIT, $-8
 	MOVB	R4, (R2)(R6.SXTX)               // 44e82638
 	MOVB	R8, (R3)(R9.UXTW)               // 68482938
 	MOVB	R10, (R5)(R8)                   // aa682838
+	MOVB	R10, (R5)(R8*1)                 // aa682838
 	MOVH	R11, (R2)(R7.SXTW<<1)           // 4bd82778
 	MOVH	R5, (R1)(R2<<1)                 // 25782278
 	MOVH	R7, (R2)(R5.SXTX<<1)            // 47f82578

src/cmd/go/internal/modfetch/cache.go

@@ -152,7 +152,7 @@ func lockVersion(mod module.Version) (unlock func(), err error) {
 // If err is nil, the caller MUST eventually call the unlock function.
 func SideLock() (unlock func(), err error) {
 	if err := checkCacheDir(); err != nil {
-		base.Fatalf("go: %v", err)
+		return nil, err
 	}
 
 	path := filepath.Join(cfg.GOMODCACHE, "cache", "lock")

src/cmd/go/internal/modget/get.go

@@ -1153,6 +1153,7 @@ func (r *resolver) loadPackages(ctx context.Context, patterns []string, findPack
 		Tags:                     imports.AnyTags(),
 		VendorModulesInGOROOTSrc: true,
 		LoadTests:                *getT,
+		AssumeRootsImported:      true, // After 'go get foo', imports of foo should build.
 		SilencePackageErrors:     true, // May be fixed by subsequent upgrades or downgrades.
 	}
 

src/cmd/go/internal/modload/buildlist.go

@@ -443,7 +443,7 @@ func expandGraph(ctx context.Context, rs *Requirements) (*Requirements, *ModuleG
 		// roots — but in a lazy module it may pull in previously-irrelevant
 		// transitive dependencies.
 
-		newRS, rsErr := updateRoots(ctx, rs.direct, rs, nil, nil)
+		newRS, rsErr := updateRoots(ctx, rs.direct, rs, nil, nil, false)
 		if rsErr != nil {
 			// Failed to update roots, perhaps because of an error in a transitive
 			// dependency needed for the update. Return the original Requirements
@@ -517,11 +517,11 @@ func tidyRoots(ctx context.Context, rs *Requirements, pkgs []*loadPkg) (*Require
 	return tidyLazyRoots(ctx, rs.direct, pkgs)
 }
 
-func updateRoots(ctx context.Context, direct map[string]bool, rs *Requirements, pkgs []*loadPkg, add []module.Version) (*Requirements, error) {
+func updateRoots(ctx context.Context, direct map[string]bool, rs *Requirements, pkgs []*loadPkg, add []module.Version, rootsImported bool) (*Requirements, error) {
 	if rs.depth == eager {
 		return updateEagerRoots(ctx, direct, rs, add)
 	}
-	return updateLazyRoots(ctx, direct, rs, pkgs, add)
+	return updateLazyRoots(ctx, direct, rs, pkgs, add, rootsImported)
 }
 
 // tidyLazyRoots returns a minimal set of root requirements that maintains the
@@ -661,7 +661,7 @@ func tidyLazyRoots(ctx context.Context, direct map[string]bool, pkgs []*loadPkg)
 //
 // (See https://golang.org/design/36460-lazy-module-loading#invariants for more
 // detail.)
-func updateLazyRoots(ctx context.Context, direct map[string]bool, rs *Requirements, pkgs []*loadPkg, add []module.Version) (*Requirements, error) {
+func updateLazyRoots(ctx context.Context, direct map[string]bool, rs *Requirements, pkgs []*loadPkg, add []module.Version, rootsImported bool) (*Requirements, error) {
 	roots := rs.rootModules
 	rootsUpgraded := false
 
@@ -688,6 +688,10 @@ func updateLazyRoots(ctx context.Context, direct map[string]bool, rs *Requiremen
 			//
 			// (This is the “import invariant” that makes lazy loading possible.)
 
+		case rootsImported && pkg.flags.has(pkgFromRoot):
+			// pkg is a transitive dependency of some root, and we are treating the
+			// roots as if they are imported by the main module (as in 'go get').
+
 		case pkg.flags.has(pkgIsRoot):
 			// pkg is a root of the package-import graph. (Generally this means that
 			// it matches a command-line argument.) We want future invocations of the

src/cmd/go/internal/modload/init.go

@@ -661,7 +661,7 @@ func requirementsFromModFile(ctx context.Context) *Requirements {
 	for _, n := range mPathCount {
 		if n > 1 {
 			var err error
-			rs, err = updateRoots(ctx, rs.direct, rs, nil, nil)
+			rs, err = updateRoots(ctx, rs.direct, rs, nil, nil, false)
 			if err != nil {
 				base.Fatalf("go: %v", err)
 			}

src/cmd/go/internal/modload/load.go

@@ -171,6 +171,11 @@ type PackageOpts struct {
 	// if the flag is set to "readonly" (the default) or "vendor".
 	ResolveMissingImports bool
 
+	// AssumeRootsImported indicates that the transitive dependencies of the root
+	// packages should be treated as if those roots will be imported by the main
+	// module.
+	AssumeRootsImported bool
+
 	// AllowPackage, if non-nil, is called after identifying the module providing
 	// each package. If AllowPackage returns a non-nil error, that error is set
 	// for the package, and the imports and test of that package will not be
@@ -875,6 +880,11 @@ const (
 	// are also roots (and must be marked pkgIsRoot).
 	pkgIsRoot
 
+	// pkgFromRoot indicates that the package is in the transitive closure of
+	// imports starting at the roots. (Note that every package marked as pkgIsRoot
+	// is also trivially marked pkgFromRoot.)
+	pkgFromRoot
+
 	// pkgImportsLoaded indicates that the imports and testImports fields of a
 	// loadPkg have been populated.
 	pkgImportsLoaded
@@ -1068,7 +1078,7 @@ func loadFromRoots(ctx context.Context, params loaderParams) *loader {
 		// iteration so we don't need to also update it here. (That would waste time
 		// computing a "direct" map that we'll have to recompute later anyway.)
 		direct := ld.requirements.direct
-		rs, err := updateRoots(ctx, direct, ld.requirements, noPkgs, toAdd)
+		rs, err := updateRoots(ctx, direct, ld.requirements, noPkgs, toAdd, ld.AssumeRootsImported)
 		if err != nil {
 			// If an error was found in a newly added module, report the package
 			// import stack instead of the module requirement stack. Packages
@@ -1274,7 +1284,7 @@ func (ld *loader) updateRequirements(ctx context.Context) (changed bool, err err
 		addRoots = tidy.rootModules
 	}
 
-	rs, err = updateRoots(ctx, direct, rs, ld.pkgs, addRoots)
+	rs, err = updateRoots(ctx, direct, rs, ld.pkgs, addRoots, ld.AssumeRootsImported)
 	if err != nil {
 		// We don't actually know what even the root requirements are supposed to be,
 		// so we can't proceed with loading. Return the error to the caller
@@ -1433,6 +1443,9 @@ func (ld *loader) applyPkgFlags(ctx context.Context, pkg *loadPkg, flags loadPkg
 		// This package matches a root pattern by virtue of being in "all".
 		flags |= pkgIsRoot
 	}
+	if flags.has(pkgIsRoot) {
+		flags |= pkgFromRoot
+	}
 
 	old := pkg.flags.update(flags)
 	new := old | flags
@@ -1487,6 +1500,12 @@ func (ld *loader) applyPkgFlags(ctx context.Context, pkg *loadPkg, flags loadPkg
 			ld.applyPkgFlags(ctx, dep, pkgInAll)
 		}
 	}
+
+	if new.has(pkgFromRoot) && !old.has(pkgFromRoot|pkgImportsLoaded) {
+		for _, dep := range pkg.imports {
+			ld.applyPkgFlags(ctx, dep, pkgFromRoot)
+		}
+	}
 }
 
 // preloadRootModules loads the module requirements needed to identify the
@@ -1549,7 +1568,7 @@ func (ld *loader) preloadRootModules(ctx context.Context, rootPkgs []string) (ch
 	}
 	module.Sort(toAdd)
 
-	rs, err := updateRoots(ctx, ld.requirements.direct, ld.requirements, nil, toAdd)
+	rs, err := updateRoots(ctx, ld.requirements.direct, ld.requirements, nil, toAdd, ld.AssumeRootsImported)
 	if err != nil {
 		// We are missing some root dependency, and for some reason we can't load
 		// enough of the module dependency graph to add the missing root. Package

src/cmd/go/testdata/script/mod_edit_no_modcache.txt

@@ -0,0 +1,15 @@
+# 'go mod edit' opportunistically locks the side-lock file in the module cache,
+# for compatibility with older versions of the 'go' command.
+# It does not otherwise depend on the module cache, so it should not
+# fail if the module cache directory cannot be created.
+
+[root] skip
+
+mkdir $WORK/readonly
+chmod 0555 $WORK/readonly
+env GOPATH=$WORK/readonly/nonexist
+
+go mod edit -go=1.17
+
+-- go.mod --
+module example.com/m

src/cmd/go/testdata/script/mod_get_lazy_indirect.txt

@@ -0,0 +1,44 @@
+# https://golang.org/issue/45979: after 'go get' on a package,
+# that package should be importable without error.
+
+
+# We start out with an unresolved dependency.
+# 'go list' suggests that we run 'go get' on that dependency.
+
+! go list -deps .
+stderr '^m.go:3:8: no required module provides package rsc\.io/quote; to add it:\n\tgo get rsc.io/quote$'
+
+
+# When we run the suggested 'go get' command, the new dependency can be used
+# immediately.
+#
+# 'go get' marks the new dependency as 'indirect', because it doesn't scan
+# enough source code to know whether it is direct, and it is easier and less
+# invasive to remove an incorrect indirect mark (e.g. using 'go get') than to
+# add one that is missing ('go mod tidy' or 'go mod vendor').
+
+go get rsc.io/quote
+grep 'rsc.io/quote v\d+\.\d+\.\d+ // indirect$' go.mod
+! grep 'rsc.io/quote v\d+\.\d+\.\d+$' go.mod
+
+go list -deps .
+! stderr .
+[!short] go build .
+[!short] ! stderr .
+
+
+# 'go get .' (or 'go mod tidy') removes the indirect mark.
+
+go get .
+grep 'rsc.io/quote v\d+\.\d+\.\d+$' go.mod
+! grep 'rsc.io/quote v\d+\.\d+\.\d+ // indirect$' go.mod
+
+
+-- go.mod --
+module example.com/m
+
+go 1.17
+-- m.go --
+package m
+
+import _ "rsc.io/quote"

src/cmd/go/testdata/script/mod_sumdb_golang.txt

@@ -10,45 +10,73 @@ go env GOSUMDB
 stdout '^sum.golang.org$'
 
 # Download direct from github.
+
 [!net] skip
 [!exec:git] skip
 env GOSUMDB=sum.golang.org
 env GOPROXY=direct
+
 go get -d rsc.io/quote@v1.5.2
 cp go.sum saved.sum
 
+
 # Download from proxy.golang.org with go.sum entry already.
 # Use 'go list' instead of 'go get' since the latter may download extra go.mod
 # files not listed in go.sum.
+
 go clean -modcache
 env GOSUMDB=
 env GOPROXY=
-go list -x -deps rsc.io/quote
+
+go list -x -m all  # Download go.mod files.
 ! stderr github
 stderr proxy.golang.org/rsc.io/quote
 ! stderr sum.golang.org/tile
 ! stderr sum.golang.org/lookup/rsc.io/quote
+
+go list -x -deps rsc.io/quote  # Download module source.
+! stderr github
+stderr proxy.golang.org/rsc.io/quote
+! stderr sum.golang.org/tile
+! stderr sum.golang.org/lookup/rsc.io/quote
+
 cmp go.sum saved.sum
 
+
 # Download again.
 # Should use the checksum database to validate new go.sum lines,
 # but not need to fetch any new data from the proxy.
+
 rm go.sum
-go list -mod=mod -x rsc.io/quote
+
+go list -mod=mod -x -m all  # Add checksums for go.mod files.
+stderr sum.golang.org/tile
 ! stderr github
 ! stderr proxy.golang.org/rsc.io/quote
-stderr sum.golang.org/tile
 stderr sum.golang.org/lookup/rsc.io/quote
+
+go list -mod=mod -x rsc.io/quote  # Add checksums for module source.
+! stderr .  # Adds checksums, but for entities already in the module cache.
+
 cmp go.sum saved.sum
 
+
 # test fallback to direct
+
 env TESTGOPROXY404=1
 go clean -modcache
 rm go.sum
-go list -mod=mod -x rsc.io/quote
+
+go list -mod=mod -x -m all  # Download go.mod files
 stderr 'proxy.golang.org.*404 testing'
 stderr github.com/rsc
+
+go list -mod=mod -x rsc.io/quote  # Download module source.
+stderr 'proxy.golang.org.*404 testing'
+stderr github.com/rsc
+
 cmp go.sum saved.sum
 
+
 -- go.mod --
 module m

src/cmd/pprof/pprof.go

@@ -233,8 +233,8 @@ func (f *file) Name() string {
 }
 
 func (f *file) ObjAddr(addr uint64) (uint64, error) {
-	// No support for shared libraries.
+	// No support for shared libraries, so translation is a no-op.
-	return 0, nil
+	return addr, nil
 }
 
 func (f *file) BuildID() string {

src/cmd/pprof/pprof_test.go

@@ -0,0 +1,127 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"fmt"
+	"internal/testenv"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+var tmp, pprofExe string // populated by buildPprof
+
+func TestMain(m *testing.M) {
+	if !testenv.HasGoBuild() {
+		return
+	}
+
+	var exitcode int
+	if err := buildPprof(); err == nil {
+		exitcode = m.Run()
+	} else {
+		fmt.Println(err)
+		exitcode = 1
+	}
+	os.RemoveAll(tmp)
+	os.Exit(exitcode)
+}
+
+func buildPprof() error {
+	var err error
+	tmp, err = os.MkdirTemp("", "TestPprof")
+	if err != nil {
+		return fmt.Errorf("TempDir failed: %v", err)
+	}
+
+	pprofExe = filepath.Join(tmp, "testpprof.exe")
+	gotool, err := testenv.GoTool()
+	if err != nil {
+		return err
+	}
+	out, err := exec.Command(gotool, "build", "-o", pprofExe, "cmd/pprof").CombinedOutput()
+	if err != nil {
+		os.RemoveAll(tmp)
+		return fmt.Errorf("go build -o %v cmd/pprof: %v\n%s", pprofExe, err, string(out))
+	}
+
+	return nil
+}
+
+// See also runtime/pprof.cpuProfilingBroken.
+func mustHaveCPUProfiling(t *testing.T) {
+	switch runtime.GOOS {
+	case "plan9":
+		t.Skipf("skipping on %s, unimplemented", runtime.GOOS)
+	case "aix":
+		t.Skipf("skipping on %s, issue 45170", runtime.GOOS)
+	case "ios", "dragonfly", "netbsd", "illumos", "solaris":
+		t.Skipf("skipping on %s, issue 13841", runtime.GOOS)
+	case "openbsd":
+		if runtime.GOARCH == "arm" || runtime.GOARCH == "arm64" {
+			t.Skipf("skipping on %s/%s, issue 13841", runtime.GOOS, runtime.GOARCH)
+		}
+	}
+}
+
+func mustHaveDisasm(t *testing.T) {
+	switch runtime.GOARCH {
+	case "mips", "mipsle", "mips64", "mips64le":
+		t.Skipf("skipping on %s, issue 12559", runtime.GOARCH)
+	case "riscv64":
+		t.Skipf("skipping on %s, issue 36738", runtime.GOARCH)
+	case "s390x":
+		t.Skipf("skipping on %s, issue 15255", runtime.GOARCH)
+	}
+
+	// Skip PIE platforms, pprof can't disassemble PIE.
+	if runtime.GOOS == "windows" {
+		t.Skipf("skipping on %s, issue 46639", runtime.GOOS)
+	}
+	if runtime.GOOS == "darwin" && runtime.GOARCH == "arm64" {
+		t.Skipf("skipping on %s/%s, issue 46639", runtime.GOOS, runtime.GOARCH)
+	}
+}
+
+// TestDisasm verifies that cmd/pprof can successfully disassemble functions.
+//
+// This is a regression test for issue 46636.
+func TestDisasm(t *testing.T) {
+	mustHaveCPUProfiling(t)
+	mustHaveDisasm(t)
+	testenv.MustHaveGoBuild(t)
+
+	tmpdir := t.TempDir()
+	cpuExe := filepath.Join(tmpdir, "cpu.exe")
+	cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", cpuExe, "cpu.go")
+	cmd.Dir = "testdata/"
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("build failed: %v\n%s", err, out)
+	}
+
+	profile := filepath.Join(tmpdir, "cpu.pprof")
+	cmd = exec.Command(cpuExe, "-output", profile)
+	out, err = cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("cpu failed: %v\n%s", err, out)
+	}
+
+	cmd = exec.Command(pprofExe, "-disasm", "main.main", cpuExe, profile)
+	out, err = cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("pprof failed: %v\n%s", err, out)
+	}
+
+	sout := string(out)
+	want := "ROUTINE ======================== main.main"
+	if !strings.Contains(sout, want) {
+		t.Errorf("pprof disasm got %s want contains %q", sout, want)
+	}
+}

src/cmd/pprof/testdata/cpu.go

@@ -0,0 +1,41 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"runtime/pprof"
+	"time"
+)
+
+var output = flag.String("output", "", "pprof profile output file")
+
+func main() {
+	flag.Parse()
+	if *output == "" {
+		fmt.Fprintf(os.Stderr, "usage: %s -output file.pprof\n", os.Args[0])
+		os.Exit(2)
+	}
+
+	f, err := os.Create(*output)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(2)
+	}
+	defer f.Close()
+
+	if err := pprof.StartCPUProfile(f); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(2)
+	}
+	defer pprof.StopCPUProfile()
+
+	// Spin for long enough to collect some samples.
+	start := time.Now()
+	for time.Since(start) < time.Second {
+	}
+}

src/database/sql/sql_test.go

@@ -2838,9 +2838,10 @@ func TestTxStmtDeadlock(t *testing.T) {
 	db := newTestDB(t, "people")
 	defer closeDB(t, db)
 
-	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Millisecond)
+	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 	tx, err := db.BeginTx(ctx, nil)
+	cancel()
 	if err != nil {
 		t.Fatal(err)
 	}

src/image/draw/draw.go

@@ -23,6 +23,16 @@ type Image interface {
 	Set(x, y int, c color.Color)
 }
 
+// RGBA64Image extends both the Image and image.RGBA64Image interfaces with a
+// SetRGBA64 method to change a single pixel. SetRGBA64 is equivalent to
+// calling Set, but it can avoid allocations from converting concrete color
+// types to the color.Color interface type.
+type RGBA64Image interface {
+	image.RGBA64Image
+	Set(x, y int, c color.Color)
+	SetRGBA64(x, y int, c color.RGBA64)
+}
+
 // Quantizer produces a palette for an image.
 type Quantizer interface {
 	// Quantize appends up to cap(p) - len(p) colors to p and returns the

src/image/image.go

@@ -45,6 +45,17 @@ type Image interface {
 	At(x, y int) color.Color
 }
 
+// RGBA64Image is an Image whose pixels can be converted directly to a
+// color.RGBA64.
+type RGBA64Image interface {
+	// RGBA64At returns the RGBA64 color of the pixel at (x, y). It is
+	// equivalent to calling At(x, y).RGBA() and converting the resulting
+	// 32-bit return values to a color.RGBA64, but it can avoid allocations
+	// from converting concrete color types to the color.Color interface type.
+	RGBA64At(x, y int) color.RGBA64
+	Image
+}
+
 // PalettedImage is an image whose colors may come from a limited palette.
 // If m is a PalettedImage and m.ColorModel() returns a color.Palette p,
 // then m.At(x, y) should be equivalent to p[m.ColorIndexAt(x, y)]. If m's
@@ -90,6 +101,24 @@ func (p *RGBA) At(x, y int) color.Color {
 	return p.RGBAAt(x, y)
 }
 
+func (p *RGBA) RGBA64At(x, y int) color.RGBA64 {
+	if !(Point{x, y}.In(p.Rect)) {
+		return color.RGBA64{}
+	}
+	i := p.PixOffset(x, y)
+	s := p.Pix[i : i+4 : i+4] // Small cap improves performance, see https://golang.org/issue/27857
+	r := uint16(s[0])
+	g := uint16(s[1])
+	b := uint16(s[2])
+	a := uint16(s[3])
+	return color.RGBA64{
+		(r << 8) | r,
+		(g << 8) | g,
+		(b << 8) | b,
+		(a << 8) | a,
+	}
+}
+
 func (p *RGBA) RGBAAt(x, y int) color.RGBA {
 	if !(Point{x, y}.In(p.Rect)) {
 		return color.RGBA{}
@@ -118,6 +147,18 @@ func (p *RGBA) Set(x, y int, c color.Color) {
 	s[3] = c1.A
 }
 
+func (p *RGBA) SetRGBA64(x, y int, c color.RGBA64) {
+	if !(Point{x, y}.In(p.Rect)) {
+		return
+	}
+	i := p.PixOffset(x, y)
+	s := p.Pix[i : i+4 : i+4] // Small cap improves performance, see https://golang.org/issue/27857
+	s[0] = uint8(c.R >> 8)
+	s[1] = uint8(c.G >> 8)
+	s[2] = uint8(c.B >> 8)
+	s[3] = uint8(c.A >> 8)
+}
+
 func (p *RGBA) SetRGBA(x, y int, c color.RGBA) {
 	if !(Point{x, y}.In(p.Rect)) {
 		return
@@ -311,6 +352,11 @@ func (p *NRGBA) At(x, y int) color.Color {
 	return p.NRGBAAt(x, y)
 }
 
+func (p *NRGBA) RGBA64At(x, y int) color.RGBA64 {
+	r, g, b, a := p.NRGBAAt(x, y).RGBA()
+	return color.RGBA64{uint16(r), uint16(g), uint16(b), uint16(a)}
+}
+
 func (p *NRGBA) NRGBAAt(x, y int) color.NRGBA {
 	if !(Point{x, y}.In(p.Rect)) {
 		return color.NRGBA{}
@@ -339,6 +385,24 @@ func (p *NRGBA) Set(x, y int, c color.Color) {
 	s[3] = c1.A
 }
 
+func (p *NRGBA) SetRGBA64(x, y int, c color.RGBA64) {
+	if !(Point{x, y}.In(p.Rect)) {
+		return
+	}
+	r, g, b, a := uint32(c.R), uint32(c.G), uint32(c.B), uint32(c.A)
+	if (a != 0) && (a != 0xffff) {
+		r = (r * 0xffff) / a
+		g = (g * 0xffff) / a
+		b = (b * 0xffff) / a
+	}
+	i := p.PixOffset(x, y)
+	s := p.Pix[i : i+4 : i+4] // Small cap improves performance, see https://golang.org/issue/27857
+	s[0] = uint8(r >> 8)
+	s[1] = uint8(g >> 8)
+	s[2] = uint8(b >> 8)
+	s[3] = uint8(a >> 8)
+}
+
 func (p *NRGBA) SetNRGBA(x, y int, c color.NRGBA) {
 	if !(Point{x, y}.In(p.Rect)) {
 		return
@@ -415,6 +479,11 @@ func (p *NRGBA64) At(x, y int) color.Color {
 	return p.NRGBA64At(x, y)
 }
 
+func (p *NRGBA64) RGBA64At(x, y int) color.RGBA64 {
+	r, g, b, a := p.NRGBA64At(x, y).RGBA()
+	return color.RGBA64{uint16(r), uint16(g), uint16(b), uint16(a)}
+}
+
 func (p *NRGBA64) NRGBA64At(x, y int) color.NRGBA64 {
 	if !(Point{x, y}.In(p.Rect)) {
 		return color.NRGBA64{}
@@ -452,6 +521,28 @@ func (p *NRGBA64) Set(x, y int, c color.Color) {
 	s[7] = uint8(c1.A)
 }
 
+func (p *NRGBA64) SetRGBA64(x, y int, c color.RGBA64) {
+	if !(Point{x, y}.In(p.Rect)) {
+		return
+	}
+	r, g, b, a := uint32(c.R), uint32(c.G), uint32(c.B), uint32(c.A)
+	if (a != 0) && (a != 0xffff) {
+		r = (r * 0xffff) / a
+		g = (g * 0xffff) / a
+		b = (b * 0xffff) / a
+	}
+	i := p.PixOffset(x, y)
+	s := p.Pix[i : i+8 : i+8] // Small cap improves performance, see https://golang.org/issue/27857
+	s[0] = uint8(r >> 8)
+	s[1] = uint8(r)
+	s[2] = uint8(g >> 8)
+	s[3] = uint8(g)
+	s[4] = uint8(b >> 8)
+	s[5] = uint8(b)
+	s[6] = uint8(a >> 8)
+	s[7] = uint8(a)
+}
+
 func (p *NRGBA64) SetNRGBA64(x, y int, c color.NRGBA64) {
 	if !(Point{x, y}.In(p.Rect)) {
 		return
@@ -532,6 +623,12 @@ func (p *Alpha) At(x, y int) color.Color {
 	return p.AlphaAt(x, y)
 }
 
+func (p *Alpha) RGBA64At(x, y int) color.RGBA64 {
+	a := uint16(p.AlphaAt(x, y).A)
+	a |= a << 8
+	return color.RGBA64{a, a, a, a}
+}
+
 func (p *Alpha) AlphaAt(x, y int) color.Alpha {
 	if !(Point{x, y}.In(p.Rect)) {
 		return color.Alpha{}
@@ -554,6 +651,14 @@ func (p *Alpha) Set(x, y int, c color.Color) {
 	p.Pix[i] = color.AlphaModel.Convert(c).(color.Alpha).A
 }
 
+func (p *Alpha) SetRGBA64(x, y int, c color.RGBA64) {
+	if !(Point{x, y}.In(p.Rect)) {
+		return
+	}
+	i := p.PixOffset(x, y)
+	p.Pix[i] = uint8(c.A >> 8)
+}
+
 func (p *Alpha) SetAlpha(x, y int, c color.Alpha) {
 	if !(Point{x, y}.In(p.Rect)) {
 		return
@@ -626,6 +731,11 @@ func (p *Alpha16) At(x, y int) color.Color {
 	return p.Alpha16At(x, y)
 }
 
+func (p *Alpha16) RGBA64At(x, y int) color.RGBA64 {
+	a := p.Alpha16At(x, y).A
+	return color.RGBA64{a, a, a, a}
+}
+
 func (p *Alpha16) Alpha16At(x, y int) color.Alpha16 {
 	if !(Point{x, y}.In(p.Rect)) {
 		return color.Alpha16{}
@@ -650,6 +760,15 @@ func (p *Alpha16) Set(x, y int, c color.Color) {
 	p.Pix[i+1] = uint8(c1.A)
 }
 
+func (p *Alpha16) SetRGBA64(x, y int, c color.RGBA64) {
+	if !(Point{x, y}.In(p.Rect)) {
+		return
+	}
+	i := p.PixOffset(x, y)
+	p.Pix[i+0] = uint8(c.A >> 8)
+	p.Pix[i+1] = uint8(c.A)
+}
+
 func (p *Alpha16) SetAlpha16(x, y int, c color.Alpha16) {
 	if !(Point{x, y}.In(p.Rect)) {
 		return
@@ -723,6 +842,12 @@ func (p *Gray) At(x, y int) color.Color {
 	return p.GrayAt(x, y)
 }
 
+func (p *Gray) RGBA64At(x, y int) color.RGBA64 {
+	gray := uint16(p.GrayAt(x, y).Y)
+	gray |= gray << 8
+	return color.RGBA64{gray, gray, gray, 0xffff}
+}
+
 func (p *Gray) GrayAt(x, y int) color.Gray {
 	if !(Point{x, y}.In(p.Rect)) {
 		return color.Gray{}
@@ -745,6 +870,16 @@ func (p *Gray) Set(x, y int, c color.Color) {
 	p.Pix[i] = color.GrayModel.Convert(c).(color.Gray).Y
 }
 
+func (p *Gray) SetRGBA64(x, y int, c color.RGBA64) {
+	if !(Point{x, y}.In(p.Rect)) {
+		return
+	}
+	// This formula is the same as in color.grayModel.
+	gray := (19595*uint32(c.R) + 38470*uint32(c.G) + 7471*uint32(c.B) + 1<<15) >> 24
+	i := p.PixOffset(x, y)
+	p.Pix[i] = uint8(gray)
+}
+
 func (p *Gray) SetGray(x, y int, c color.Gray) {
 	if !(Point{x, y}.In(p.Rect)) {
 		return
@@ -804,6 +939,11 @@ func (p *Gray16) At(x, y int) color.Color {
 	return p.Gray16At(x, y)
 }
 
+func (p *Gray16) RGBA64At(x, y int) color.RGBA64 {
+	gray := p.Gray16At(x, y).Y
+	return color.RGBA64{gray, gray, gray, 0xffff}
+}
+
 func (p *Gray16) Gray16At(x, y int) color.Gray16 {
 	if !(Point{x, y}.In(p.Rect)) {
 		return color.Gray16{}
@@ -828,6 +968,17 @@ func (p *Gray16) Set(x, y int, c color.Color) {
 	p.Pix[i+1] = uint8(c1.Y)
 }
 
+func (p *Gray16) SetRGBA64(x, y int, c color.RGBA64) {
+	if !(Point{x, y}.In(p.Rect)) {
+		return
+	}
+	// This formula is the same as in color.gray16Model.
+	gray := (19595*uint32(c.R) + 38470*uint32(c.G) + 7471*uint32(c.B) + 1<<15) >> 16
+	i := p.PixOffset(x, y)
+	p.Pix[i+0] = uint8(gray >> 8)
+	p.Pix[i+1] = uint8(gray)
+}
+
 func (p *Gray16) SetGray16(x, y int, c color.Gray16) {
 	if !(Point{x, y}.In(p.Rect)) {
 		return
@@ -888,6 +1039,11 @@ func (p *CMYK) At(x, y int) color.Color {
 	return p.CMYKAt(x, y)
 }
 
+func (p *CMYK) RGBA64At(x, y int) color.RGBA64 {
+	r, g, b, a := p.CMYKAt(x, y).RGBA()
+	return color.RGBA64{uint16(r), uint16(g), uint16(b), uint16(a)}
+}
+
 func (p *CMYK) CMYKAt(x, y int) color.CMYK {
 	if !(Point{x, y}.In(p.Rect)) {
 		return color.CMYK{}
@@ -916,6 +1072,19 @@ func (p *CMYK) Set(x, y int, c color.Color) {
 	s[3] = c1.K
 }
 
+func (p *CMYK) SetRGBA64(x, y int, c color.RGBA64) {
+	if !(Point{x, y}.In(p.Rect)) {
+		return
+	}
+	cc, mm, yy, kk := color.RGBToCMYK(uint8(c.R>>8), uint8(c.G>>8), uint8(c.B>>8))
+	i := p.PixOffset(x, y)
+	s := p.Pix[i : i+4 : i+4] // Small cap improves performance, see https://golang.org/issue/27857
+	s[0] = cc
+	s[1] = mm
+	s[2] = yy
+	s[3] = kk
+}
+
 func (p *CMYK) SetCMYK(x, y int, c color.CMYK) {
 	if !(Point{x, y}.In(p.Rect)) {
 		return
@@ -988,6 +1157,26 @@ func (p *Paletted) At(x, y int) color.Color {
 	return p.Palette[p.Pix[i]]
 }
 
+func (p *Paletted) RGBA64At(x, y int) color.RGBA64 {
+	if len(p.Palette) == 0 {
+		return color.RGBA64{}
+	}
+	c := color.Color(nil)
+	if !(Point{x, y}.In(p.Rect)) {
+		c = p.Palette[0]
+	} else {
+		i := p.PixOffset(x, y)
+		c = p.Palette[p.Pix[i]]
+	}
+	r, g, b, a := c.RGBA()
+	return color.RGBA64{
+		uint16(r),
+		uint16(g),
+		uint16(b),
+		uint16(a),
+	}
+}
+
 // PixOffset returns the index of the first element of Pix that corresponds to
 // the pixel at (x, y).
 func (p *Paletted) PixOffset(x, y int) int {
@@ -1002,6 +1191,14 @@ func (p *Paletted) Set(x, y int, c color.Color) {
 	p.Pix[i] = uint8(p.Palette.Index(c))
 }
 
+func (p *Paletted) SetRGBA64(x, y int, c color.RGBA64) {
+	if !(Point{x, y}.In(p.Rect)) {
+		return
+	}
+	i := p.PixOffset(x, y)
+	p.Pix[i] = uint8(p.Palette.Index(c))
+}
+
 func (p *Paletted) ColorIndexAt(x, y int) uint8 {
 	if !(Point{x, y}.In(p.Rect)) {
 		return 0

src/image/image_test.go

@@ -6,6 +6,7 @@ package image
 
 import (
 	"image/color"
+	"image/color/palette"
 	"testing"
 )
 
@@ -191,6 +192,80 @@ func Test16BitsPerColorChannel(t *testing.T) {
 	}
 }
 
+func TestRGBA64Image(t *testing.T) {
+	// memset sets every element of s to v.
+	memset := func(s []byte, v byte) {
+		for i := range s {
+			s[i] = v
+		}
+	}
+
+	r := Rect(0, 0, 3, 2)
+	testCases := []Image{
+		NewAlpha(r),
+		NewAlpha16(r),
+		NewCMYK(r),
+		NewGray(r),
+		NewGray16(r),
+		NewNRGBA(r),
+		NewNRGBA64(r),
+		NewNYCbCrA(r, YCbCrSubsampleRatio444),
+		NewPaletted(r, palette.Plan9),
+		NewRGBA(r),
+		NewRGBA64(r),
+		NewYCbCr(r, YCbCrSubsampleRatio444),
+	}
+	for _, tc := range testCases {
+		switch tc := tc.(type) {
+		// Most of the concrete image types in the testCases implement the
+		// draw.RGBA64Image interface: they have a SetRGBA64 method. We use an
+		// interface literal here, instead of importing "image/draw", to avoid
+		// an import cycle.
+		//
+		// The YCbCr and NYCbCrA types are special-cased. Chroma subsampling
+		// means that setting one pixel can modify neighboring pixels. They
+		// don't have Set or SetRGBA64 methods because that side effect could
+		// be surprising. Here, we just memset the channel buffers instead.
+		case interface {
+			SetRGBA64(x, y int, c color.RGBA64)
+		}:
+			tc.SetRGBA64(1, 1, color.RGBA64{0x7FFF, 0x3FFF, 0x0000, 0x7FFF})
+
+		case *NYCbCrA:
+			memset(tc.YCbCr.Y, 0x77)
+			memset(tc.YCbCr.Cb, 0x88)
+			memset(tc.YCbCr.Cr, 0x99)
+			memset(tc.A, 0xAA)
+
+		case *YCbCr:
+			memset(tc.Y, 0x77)
+			memset(tc.Cb, 0x88)
+			memset(tc.Cr, 0x99)
+
+		default:
+			t.Errorf("could not initialize pixels for %T", tc)
+			continue
+		}
+
+		// Check that RGBA64At(x, y) is equivalent to At(x, y).RGBA().
+		rgba64Image, ok := tc.(RGBA64Image)
+		if !ok {
+			t.Errorf("%T is not an RGBA64Image", tc)
+			continue
+		}
+		got := rgba64Image.RGBA64At(1, 1)
+		wantR, wantG, wantB, wantA := tc.At(1, 1).RGBA()
+		if (uint32(got.R) != wantR) || (uint32(got.G) != wantG) ||
+			(uint32(got.B) != wantB) || (uint32(got.A) != wantA) {
+			t.Errorf("%T:\ngot  (0x%04X, 0x%04X, 0x%04X, 0x%04X)\n"+
+				"want (0x%04X, 0x%04X, 0x%04X, 0x%04X)", tc,
+				got.R, got.G, got.B, got.A,
+				wantR, wantG, wantB, wantA)
+			continue
+		}
+	}
+}
+
 func BenchmarkAt(b *testing.B) {
 	for _, tc := range testImages {
 		b.Run(tc.name, func(b *testing.B) {

src/image/ycbcr.go

@@ -71,6 +71,11 @@ func (p *YCbCr) At(x, y int) color.Color {
 	return p.YCbCrAt(x, y)
 }
 
+func (p *YCbCr) RGBA64At(x, y int) color.RGBA64 {
+	r, g, b, a := p.YCbCrAt(x, y).RGBA()
+	return color.RGBA64{uint16(r), uint16(g), uint16(b), uint16(a)}
+}
+
 func (p *YCbCr) YCbCrAt(x, y int) color.YCbCr {
 	if !(Point{x, y}.In(p.Rect)) {
 		return color.YCbCr{}
@@ -210,6 +215,11 @@ func (p *NYCbCrA) At(x, y int) color.Color {
 	return p.NYCbCrAAt(x, y)
 }
 
+func (p *NYCbCrA) RGBA64At(x, y int) color.RGBA64 {
+	r, g, b, a := p.NYCbCrAAt(x, y).RGBA()
+	return color.RGBA64{uint16(r), uint16(g), uint16(b), uint16(a)}
+}
+
 func (p *NYCbCrA) NYCbCrAAt(x, y int) color.NYCbCrA {
 	if !(Point{X: x, Y: y}.In(p.Rect)) {
 		return color.NYCbCrA{}

src/math/rand/rand.go

@@ -12,9 +12,6 @@
 // The default Source is safe for concurrent use by multiple goroutines, but
 // Sources created by NewSource are not.
 //
-// Mathematical interval notation such as [0, n) is used throughout the
-// documentation for this package.
-//
 // This package's outputs might be easily predictable regardless of how it's
 // seeded. For random numbers suitable for security-sensitive work, see the
 // crypto/rand package.
@@ -106,7 +103,7 @@ func (r *Rand) Int() int {
 	return int(u << 1 >> 1) // clear sign bit if int == int32
 }
 
-// Int63n returns, as an int64, a non-negative pseudo-random number in [0,n).
+// Int63n returns, as an int64, a non-negative pseudo-random number in the half-open interval [0,n).
 // It panics if n <= 0.
 func (r *Rand) Int63n(n int64) int64 {
 	if n <= 0 {
@@ -123,7 +120,7 @@ func (r *Rand) Int63n(n int64) int64 {
 	return v % n
 }
 
-// Int31n returns, as an int32, a non-negative pseudo-random number in [0,n).
+// Int31n returns, as an int32, a non-negative pseudo-random number in the half-open interval [0,n).
 // It panics if n <= 0.
 func (r *Rand) Int31n(n int32) int32 {
 	if n <= 0 {
@@ -140,7 +137,7 @@ func (r *Rand) Int31n(n int32) int32 {
 	return v % n
 }
 
-// int31n returns, as an int32, a non-negative pseudo-random number in [0,n).
+// int31n returns, as an int32, a non-negative pseudo-random number in the half-open interval [0,n).
 // n must be > 0, but int31n does not check this; the caller must ensure it.
 // int31n exists because Int31n is inefficient, but Go 1 compatibility
 // requires that the stream of values produced by math/rand remain unchanged.
@@ -164,7 +161,7 @@ func (r *Rand) int31n(n int32) int32 {
 	return int32(prod >> 32)
 }
 
-// Intn returns, as an int, a non-negative pseudo-random number in [0,n).
+// Intn returns, as an int, a non-negative pseudo-random number in the half-open interval [0,n).
 // It panics if n <= 0.
 func (r *Rand) Intn(n int) int {
 	if n <= 0 {
@@ -176,7 +173,7 @@ func (r *Rand) Intn(n int) int {
 	return int(r.Int63n(int64(n)))
 }
 
-// Float64 returns, as a float64, a pseudo-random number in [0.0,1.0).
+// Float64 returns, as a float64, a pseudo-random number in the half-open interval [0.0,1.0).
 func (r *Rand) Float64() float64 {
 	// A clearer, simpler implementation would be:
 	//	return float64(r.Int63n(1<<53)) / (1<<53)
@@ -202,7 +199,7 @@ again:
 	return f
 }
 
-// Float32 returns, as a float32, a pseudo-random number in [0.0,1.0).
+// Float32 returns, as a float32, a pseudo-random number in the half-open interval [0.0,1.0).
 func (r *Rand) Float32() float32 {
 	// Same rationale as in Float64: we want to preserve the Go 1 value
 	// stream except we want to fix it not to return 1.0
@@ -215,7 +212,8 @@ again:
 	return f
 }
 
-// Perm returns, as a slice of n ints, a pseudo-random permutation of the integers [0,n).
+// Perm returns, as a slice of n ints, a pseudo-random permutation of the integers
+// in the half-open interval [0,n).
 func (r *Rand) Perm(n int) []int {
 	m := make([]int, n)
 	// In the following loop, the iteration when i=0 always swaps m[0] with m[0].
@@ -323,31 +321,31 @@ func Int31() int32 { return globalRand.Int31() }
 // Int returns a non-negative pseudo-random int from the default Source.
 func Int() int { return globalRand.Int() }
 
-// Int63n returns, as an int64, a non-negative pseudo-random number in [0,n)
+// Int63n returns, as an int64, a non-negative pseudo-random number in the half-open interval [0,n)
 // from the default Source.
 // It panics if n <= 0.
 func Int63n(n int64) int64 { return globalRand.Int63n(n) }
 
-// Int31n returns, as an int32, a non-negative pseudo-random number in [0,n)
+// Int31n returns, as an int32, a non-negative pseudo-random number in the half-open interval [0,n)
 // from the default Source.
 // It panics if n <= 0.
 func Int31n(n int32) int32 { return globalRand.Int31n(n) }
 
-// Intn returns, as an int, a non-negative pseudo-random number in [0,n)
+// Intn returns, as an int, a non-negative pseudo-random number in the half-open interval [0,n)
 // from the default Source.
 // It panics if n <= 0.
 func Intn(n int) int { return globalRand.Intn(n) }
 
-// Float64 returns, as a float64, a pseudo-random number in [0.0,1.0)
+// Float64 returns, as a float64, a pseudo-random number in the half-open interval [0.0,1.0)
 // from the default Source.
 func Float64() float64 { return globalRand.Float64() }
 
-// Float32 returns, as a float32, a pseudo-random number in [0.0,1.0)
+// Float32 returns, as a float32, a pseudo-random number in the half-open interval [0.0,1.0)
 // from the default Source.
 func Float32() float32 { return globalRand.Float32() }
 
-// Perm returns, as a slice of n ints, a pseudo-random permutation of the integers [0,n)
+// Perm returns, as a slice of n ints, a pseudo-random permutation of the integers
-// from the default Source.
+// in the half-open interval [0,n) from the default Source.
 func Perm(n int) []int { return globalRand.Perm(n) }
 
 // Shuffle pseudo-randomizes the order of elements using the default Source.

src/os/signal/signal_test.go

@@ -32,6 +32,11 @@ import (
 // The current value is set based on flakes observed in the Go builders.
 var settleTime = 100 * time.Millisecond
 
+// fatalWaitingTime is an absurdly long time to wait for signals to be
+// delivered but, using it, we (hopefully) eliminate test flakes on the
+// build servers. See #46736 for discussion.
+var fatalWaitingTime = 30 * time.Second
+
 func init() {
 	if testenv.Builder() == "solaris-amd64-oraclerel" {
 		// The solaris-amd64-oraclerel builder has been observed to time out in
@@ -84,7 +89,7 @@ func waitSig1(t *testing.T, c <-chan os.Signal, sig os.Signal, all bool) {
 	// General user code should filter out all unexpected signals instead of just
 	// SIGURG, but since os/signal is tightly coupled to the runtime it seems
 	// appropriate to be stricter here.
-	for time.Since(start) < settleTime {
+	for time.Since(start) < fatalWaitingTime {
 		select {
 		case s := <-c:
 			if s == sig {
@@ -97,7 +102,7 @@ func waitSig1(t *testing.T, c <-chan os.Signal, sig os.Signal, all bool) {
 			timer.Reset(settleTime / 10)
 		}
 	}
-	t.Fatalf("timeout after %v waiting for %v", settleTime, sig)
+	t.Fatalf("timeout after %v waiting for %v", fatalWaitingTime, sig)
 }
 
 // quiesce waits until we can be reasonably confident that all pending signals

src/runtime/example_test.go

@@ -12,12 +12,15 @@ import (
 
 func ExampleFrames() {
 	c := func() {
-		// Ask runtime.Callers for up to 10 pcs, including runtime.Callers itself.
+		// Ask runtime.Callers for up to 10 PCs, including runtime.Callers itself.
 		pc := make([]uintptr, 10)
 		n := runtime.Callers(0, pc)
 		if n == 0 {
-			// No pcs available. Stop now.
+			// No PCs available. This can happen if the first argument to
-			// This can happen if the first argument to runtime.Callers is large.
+			// runtime.Callers is large.
+			//
+			// Return now to avoid processing the zero Frame that would
+			// otherwise be returned by frames.Next below.
 			return
 		}
 
@@ -25,9 +28,12 @@ func ExampleFrames() {
 		frames := runtime.CallersFrames(pc)
 
 		// Loop to get frames.
-		// A fixed number of pcs can expand to an indefinite number of Frames.
+		// A fixed number of PCs can expand to an indefinite number of Frames.
 		for {
 			frame, more := frames.Next()
+
+			// Process this frame.
+			//
 			// To keep this example's output stable
 			// even if there are changes in the testing package,
 			// stop unwinding when we leave package runtime.
@@ -35,6 +41,8 @@ func ExampleFrames() {
 				break
 			}
 			fmt.Printf("- more:%v | %s\n", more, frame.Function)
+
+			// Check whether there are more frames to process after this one.
 			if !more {
 				break
 			}

src/runtime/pprof/pprof_test.go

@@ -261,6 +261,27 @@ func parseProfile(t *testing.T, valBytes []byte, f func(uintptr, []*profile.Loca
 	return p
 }
 
+func cpuProfilingBroken() bool {
+	switch runtime.GOOS {
+	case "plan9":
+		// Profiling unimplemented.
+		return true
+	case "aix":
+		// See https://golang.org/issue/45170.
+		return true
+	case "ios", "dragonfly", "netbsd", "illumos", "solaris":
+		// See https://golang.org/issue/13841.
+		return true
+	case "openbsd":
+		if runtime.GOARCH == "arm" || runtime.GOARCH == "arm64" {
+			// See https://golang.org/issue/13841.
+			return true
+		}
+	}
+
+	return false
+}
+
 // testCPUProfile runs f under the CPU profiler, checking for some conditions specified by need,
 // as interpreted by matches, and returns the parsed profile.
 func testCPUProfile(t *testing.T, matches matchFunc, need []string, avoid []string, f func(dur time.Duration)) *profile.Profile {
@@ -276,16 +297,7 @@ func testCPUProfile(t *testing.T, matches matchFunc, need []string, avoid []stri
 		t.Skip("skipping on plan9")
 	}
 
-	broken := false
+	broken := cpuProfilingBroken()
-	switch runtime.GOOS {
-	// See https://golang.org/issue/45170 for AIX.
-	case "ios", "dragonfly", "netbsd", "illumos", "solaris", "aix":
-		broken = true
-	case "openbsd":
-		if runtime.GOARCH == "arm" || runtime.GOARCH == "arm64" {
-			broken = true
-		}
-	}
 
 	maxDuration := 5 * time.Second
 	if testing.Short() && broken {
@@ -612,7 +624,7 @@ func growstack1() {
 
 //go:noinline
 func growstack(n int) {
-	var buf [8 << 16]byte
+	var buf [8 << 18]byte
 	use(buf)
 	if n > 0 {
 		growstack(n - 1)
@@ -620,7 +632,7 @@ func growstack(n int) {
 }
 
 //go:noinline
-func use(x [8 << 16]byte) {}
+func use(x [8 << 18]byte) {}
 
 func TestBlockProfile(t *testing.T) {
 	type TestCase struct {

src/runtime/signal_unix.go

@@ -281,6 +281,8 @@ func setProcessCPUProfiler(hz int32) {
 		it.it_value = it.it_interval
 		setitimer(_ITIMER_PROF, &it, nil)
 	} else {
+		setitimer(_ITIMER_PROF, &itimerval{}, nil)
+
 		// If the Go signal handler should be disabled by default,
 		// switch back to the signal handler that was installed
 		// when we enabled profiling. We don't try to handle the case
@@ -304,8 +306,6 @@ func setProcessCPUProfiler(hz int32) {
 				setsig(_SIGPROF, h)
 			}
 		}
-
-		setitimer(_ITIMER_PROF, &itimerval{}, nil)
 	}
 }
 
@@ -383,7 +383,7 @@ func preemptM(mp *m) {
 //go:nosplit
 func sigFetchG(c *sigctxt) *g {
 	switch GOARCH {
-	case "arm", "arm64":
+	case "arm", "arm64", "ppc64", "ppc64le":
 		if !iscgo && inVDSOPage(c.sigpc()) {
 			// When using cgo, we save the g on TLS and load it from there
 			// in sigtramp. Just use that.

src/runtime/symtab.go

@@ -69,8 +69,15 @@ func CallersFrames(callers []uintptr) *Frames {
 	return f
 }
 
-// Next returns frame information for the next caller.
+// Next returns a Frame representing the next call frame in the slice
-// If more is false, there are no more callers (the Frame value is valid).
+// of PC values. If it has already returned all call frames, Next
+// returns a zero Frame.
+//
+// The more result indicates whether the next call to Next will return
+// a valid Frame. It does not necessarily indicate whether this call
+// returned one.
+//
+// See the Frames example for idiomatic usage.
 func (ci *Frames) Next() (frame Frame, more bool) {
 	for len(ci.frames) < 2 {
 		// Find the next frame.

src/runtime/sys_linux_ppc64x.s

@@ -216,15 +216,45 @@ TEXT runtime·walltime(SB),NOSPLIT,$16-12
 	MOVD	(g_sched+gobuf_sp)(R7), R1	// Set SP to g0 stack
 
 noswitch:
-	SUB	$16, R1			// Space for results
+	SUB	$16, R1                 // Space for results
-	RLDICR	$0, R1, $59, R1		// Align for C code
+	RLDICR	$0, R1, $59, R1         // Align for C code
 	MOVD	R12, CTR
 	MOVD	R1, R4
-	BL	(CTR)			// Call from VDSO
+
-	MOVD	$0, R0			// Restore R0
+	// Store g on gsignal's stack, so if we receive a signal
-	MOVD	0(R1), R3		// sec
+	// during VDSO code we can find the g.
-	MOVD	8(R1), R5		// nsec
+	// If we don't have a signal stack, we won't receive signal,
-	MOVD	R15, R1			// Restore SP
+	// so don't bother saving g.
+	// When using cgo, we already saved g on TLS, also don't save
+	// g here.
+	// Also don't save g if we are already on the signal stack.
+	// We won't get a nested signal.
+	MOVBZ	runtime·iscgo(SB), R22
+	CMP	R22, $0
+	BNE	nosaveg
+	MOVD	m_gsignal(R21), R22	// g.m.gsignal
+	CMP	R22, $0
+	BEQ	nosaveg
+
+	CMP	g, R22
+	BEQ	nosaveg
+	MOVD	(g_stack+stack_lo)(R22), R22 // g.m.gsignal.stack.lo
+	MOVD	g, (R22)
+
+	BL	(CTR)	// Call from VDSO
+
+	MOVD	$0, (R22)	// clear g slot, R22 is unchanged by C code
+
+	JMP	finish
+
+nosaveg:
+	BL	(CTR)	// Call from VDSO
+
+finish:
+	MOVD	$0, R0		// Restore R0
+	MOVD	0(R1), R3	// sec
+	MOVD	8(R1), R5	// nsec
+	MOVD	R15, R1		// Restore SP
 
 	// Restore vdsoPC, vdsoSP
 	// We don't worry about being signaled between the two stores.
@@ -236,7 +266,7 @@ noswitch:
 	MOVD	32(R1), R6
 	MOVD	R6, m_vdsoPC(R21)
 
-finish:
+return:
 	MOVD	R3, sec+0(FP)
 	MOVW	R5, nsec+8(FP)
 	RET
@@ -247,7 +277,7 @@ fallback:
 	SYSCALL $SYS_clock_gettime
 	MOVD	32(R1), R3
 	MOVD	40(R1), R5
-	JMP	finish
+	JMP	return
 
 TEXT runtime·nanotime1(SB),NOSPLIT,$16-8
 	MOVD	$1, R3		// CLOCK_MONOTONIC
@@ -283,7 +313,37 @@ noswitch:
 	RLDICR	$0, R1, $59, R1		// Align for C code
 	MOVD	R12, CTR
 	MOVD	R1, R4
-	BL	(CTR)			// Call from VDSO
+
+	// Store g on gsignal's stack, so if we receive a signal
+	// during VDSO code we can find the g.
+	// If we don't have a signal stack, we won't receive signal,
+	// so don't bother saving g.
+	// When using cgo, we already saved g on TLS, also don't save
+	// g here.
+	// Also don't save g if we are already on the signal stack.
+	// We won't get a nested signal.
+	MOVBZ	runtime·iscgo(SB), R22
+	CMP	R22, $0
+	BNE	nosaveg
+	MOVD	m_gsignal(R21), R22	// g.m.gsignal
+	CMP	R22, $0
+	BEQ	nosaveg
+
+	CMP	g, R22
+	BEQ	nosaveg
+	MOVD	(g_stack+stack_lo)(R22), R22 // g.m.gsignal.stack.lo
+	MOVD	g, (R22)
+
+	BL	(CTR)	// Call from VDSO
+
+	MOVD	$0, (R22)	// clear g slot, R22 is unchanged by C code
+
+	JMP	finish
+
+nosaveg:
+	BL	(CTR)	// Call from VDSO
+
+finish:
 	MOVD	$0, R0			// Restore R0
 	MOVD	0(R1), R3		// sec
 	MOVD	8(R1), R5		// nsec
@@ -299,7 +359,7 @@ noswitch:
 	MOVD	32(R1), R6
 	MOVD	R6, m_vdsoPC(R21)
 
-finish:
+return:
 	// sec is in R3, nsec in R5
 	// return nsec in R3
 	MOVD	$1000000000, R4
@@ -314,7 +374,7 @@ fallback:
 	SYSCALL $SYS_clock_gettime
 	MOVD	32(R1), R3
 	MOVD	40(R1), R5
-	JMP	finish
+	JMP	return
 
 TEXT runtime·rtsigprocmask(SB),NOSPLIT|NOFRAME,$0-28
 	MOVW	how+0(FP), R3
@@ -469,7 +529,7 @@ TEXT sigtramp<>(SB),NOSPLIT|NOFRAME,$0
 	// this might be called in external code context,
 	// where g is not set.
 	MOVBZ	runtime·iscgo(SB), R6
-	CMP 	R6, $0
+	CMP	R6, $0
 	BEQ	2(PC)
 	BL	runtime·load_g(SB)
 

src/testing/testing.go

@@ -252,6 +252,8 @@ import (
 	"sync"
 	"sync/atomic"
 	"time"
+	"unicode"
+	"unicode/utf8"
 )
 
 var initRan bool
@@ -908,11 +910,6 @@ func (c *common) Cleanup(f func()) {
 	c.cleanups = append(c.cleanups, fn)
 }
 
-var tempDirReplacer struct {
-	sync.Once
-	r *strings.Replacer
-}
-
 // TempDir returns a temporary directory for the test to use.
 // The directory is automatically removed by Cleanup when the test and
 // all its subtests complete.
@@ -936,13 +933,26 @@ func (c *common) TempDir() string {
 	if nonExistent {
 		c.Helper()
 
-		// os.MkdirTemp doesn't like path separators in its pattern,
+		// Drop unusual characters (such as path separators or
-		// so mangle the name to accommodate subtests.
+		// characters interacting with globs) from the directory name to
-		tempDirReplacer.Do(func() {
+		// avoid surprising os.MkdirTemp behavior.
-			tempDirReplacer.r = strings.NewReplacer("/", "_", "\\", "_", ":", "_")
+		mapper := func(r rune) rune {
-		})
+			if r < utf8.RuneSelf {
-		pattern := tempDirReplacer.r.Replace(c.Name())
+				const allowed = "!#$%&()+,-.=@^_{}~ "
-
+				if '0' <= r && r <= '9' ||
+					'a' <= r && r <= 'z' ||
+					'A' <= r && r <= 'Z' {
+					return r
+				}
+				if strings.ContainsRune(allowed, r) {
+					return r
+				}
+			} else if unicode.IsLetter(r) || unicode.IsNumber(r) {
+				return r
+			}
+			return -1
+		}
+		pattern := strings.Map(mapper, c.Name())
 		c.tempDir, c.tempDirErr = os.MkdirTemp("", pattern)
 		if c.tempDirErr == nil {
 			c.Cleanup(func() {

src/testing/testing_test.go

@@ -58,6 +58,9 @@ func TestTempDir(t *testing.T) {
 	t.Run("test:subtest", testTempDir)
 	t.Run("test/..", testTempDir)
 	t.Run("../test", testTempDir)
+	t.Run("test[]", testTempDir)
+	t.Run("test*", testTempDir)
+	t.Run("äöüéè", testTempDir)
 }
 
 func testTempDir(t *testing.T) {
@@ -74,7 +77,7 @@ func testTempDir(t *testing.T) {
 			if err != nil {
 				t.Fatal(err)
 			}
-			t.Errorf("directory %q stil exists: %v, isDir=%v", dir, fi, fi.IsDir())
+			t.Errorf("directory %q still exists: %v, isDir=%v", dir, fi, fi.IsDir())
 		default:
 			if !t.Failed() {
 				t.Fatal("never received dir channel")
@@ -108,6 +111,11 @@ func testTempDir(t *testing.T) {
 	if len(files) > 0 {
 		t.Errorf("unexpected %d files in TempDir: %v", len(files), files)
 	}
+
+	glob := filepath.Join(dir, "*.txt")
+	if _, err := filepath.Glob(glob); err != nil {
+		t.Error(err)
+	}
 }
 
 func TestSetenv(t *testing.T) {

src/time/time.go

@@ -1340,7 +1340,7 @@ func UnixMicro(usec int64) Time {
 }
 
 // IsDST reports whether the time in the configured location is in Daylight Savings Time.
-func (t *Time) IsDST() bool {
+func (t Time) IsDST() bool {
 	_, _, _, _, isDST := t.loc.lookup(t.Unix())
 	return isDST
 }