diff --git a/src/cmd/go.mod b/src/cmd/go.mod
index ab756c8007..55ef2395c5 100644
--- a/src/cmd/go.mod
+++ b/src/cmd/go.mod
@@ -7,7 +7,7 @@ require (
 	github.com/ianlancetaylor/demangle v0.0.0-20180524225900-fc6590592b44 // indirect
 	golang.org/x/arch v0.0.0-20190815191158-8a70ba74b3a1
 	golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550
-	golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee
+	golang.org/x/mod v0.1.1-0.20191126161957-788aebd06792
 	golang.org/x/sys v0.0.0-20190502175342-a43fa875dd82 // indirect
-	golang.org/x/tools v0.0.0-20191104222624-6b7b8b79ae80
+	golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e
 )
diff --git a/src/cmd/go.sum b/src/cmd/go.sum
index 09bfadab81..040f25b617 100644
--- a/src/cmd/go.sum
+++ b/src/cmd/go.sum
@@ -7,8 +7,8 @@ golang.org/x/arch v0.0.0-20190815191158-8a70ba74b3a1/go.mod h1:flIaEI6LNU6xOCD5P
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550 h1:ObdrDkeb4kJdCP557AjRjq69pTHfNouLtWZG7j9rPN8=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
-golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee h1:WG0RUwxtNT4qqaXX3DPA8zHFNm/D9xaBpxzHt1WcA/E=
-golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee/go.mod h1:QqPTAvyqsEbceGzBzNggFXnrqF1CaUcvgkdR5Ot7KZg=
+golang.org/x/mod v0.1.1-0.20191126161957-788aebd06792 h1:04Uqz7R2BD7irAGgQtrKNW5tLa50RgSW71y4ofoaivk=
+golang.org/x/mod v0.1.1-0.20191126161957-788aebd06792/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
@@ -18,8 +18,8 @@ golang.org/x/sys v0.0.0-20190502175342-a43fa875dd82 h1:vsphBvatvfbhlb4PO1BYSr9dz
 golang.org/x/sys v0.0.0-20190502175342-a43fa875dd82/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-golang.org/x/tools v0.0.0-20191104222624-6b7b8b79ae80 h1:6CcDC1SXj4DrJP955osT9RJmKsH3LQBZJ59D5v4Rw0s=
-golang.org/x/tools v0.0.0-20191104222624-6b7b8b79ae80/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e h1:aZzprAO9/8oim3qStq3wc1Xuxx4QmAGriC4VU4ojemQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898 h1:/atklqdjdhuosWIl6AIbOeHJjicWYPqR9bpxqxYG2pA=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
diff --git a/src/cmd/vendor/golang.org/x/mod/modfile/rule.go b/src/cmd/vendor/golang.org/x/mod/modfile/rule.go
index 292d5b60b5..62af06889f 100644
--- a/src/cmd/vendor/golang.org/x/mod/modfile/rule.go
+++ b/src/cmd/vendor/golang.org/x/mod/modfile/rule.go
@@ -313,8 +313,8 @@ func isIndirect(line *Line) bool {
 	if len(line.Suffix) == 0 {
 		return false
 	}
-	f := strings.Fields(line.Suffix[0].Token)
-	return (len(f) == 2 && f[1] == "indirect" || len(f) > 2 && f[1] == "indirect;") && f[0] == "//"
+	f := strings.Fields(strings.TrimPrefix(line.Suffix[0].Token, string(slashSlash)))
+	return (len(f) == 1 && f[0] == "indirect" || len(f) > 1 && f[0] == "indirect;")
 }
 
 // setIndirect sets line to have (or not have) a "// indirect" comment.
@@ -329,13 +329,17 @@ func setIndirect(line *Line, indirect bool) {
 			line.Suffix = []Comment{{Token: "// indirect", Suffix: true}}
 			return
 		}
-		// Insert at beginning of existing comment.
+
 		com := &line.Suffix[0]
-		space := " "
-		if len(com.Token) > 2 && com.Token[2] == ' ' || com.Token[2] == '\t' {
-			space = ""
+		text := strings.TrimSpace(strings.TrimPrefix(com.Token, string(slashSlash)))
+		if text == "" {
+			// Empty comment.
+			com.Token = "// indirect"
+			return
 		}
-		com.Token = "// indirect;" + space + com.Token[2:]
+
+		// Insert at beginning of existing comment.
+		com.Token = "// indirect; " + text
 		return
 	}
 
diff --git a/src/cmd/vendor/golang.org/x/mod/module/module.go b/src/cmd/vendor/golang.org/x/mod/module/module.go
index 21f123957d..6cd37280a8 100644
--- a/src/cmd/vendor/golang.org/x/mod/module/module.go
+++ b/src/cmd/vendor/golang.org/x/mod/module/module.go
@@ -123,8 +123,12 @@ type Version struct {
 	Version string `json:",omitempty"`
 }
 
-// String returns the module version syntax Path@Version.
+// String returns a representation of the Version suitable for logging
+// (Path@Version, or just Path if Version is empty).
 func (m Version) String() string {
+	if m.Version == "" {
+		return m.Path
+	}
 	return m.Path + "@" + m.Version
 }
 
diff --git a/src/cmd/vendor/golang.org/x/mod/zip/zip.go b/src/cmd/vendor/golang.org/x/mod/zip/zip.go
index d2811def7a..37c764257e 100644
--- a/src/cmd/vendor/golang.org/x/mod/zip/zip.go
+++ b/src/cmd/vendor/golang.org/x/mod/zip/zip.go
@@ -234,6 +234,8 @@ func Create(w io.Writer, m module.Version, files []File) (err error) {
 // belong in the module zip. In particular, CreateFromDir will not include
 // files in modules found in subdirectories, most files in vendor directories,
 // or irregular files (such as symbolic links) in the output archive.
+// Additionally, unlike Create, CreateFromDir will not include directories
+// named ".bzr", ".git", ".hg", or ".svn".
 func CreateFromDir(w io.Writer, m module.Version, dir string) (err error) {
 	defer func() {
 		if zerr, ok := err.(*zipError); ok {
@@ -257,6 +259,14 @@ func CreateFromDir(w io.Writer, m module.Version, dir string) (err error) {
 				return nil
 			}
 
+			// Skip VCS directories.
+			// fossil repos are regular files with arbitrary names, so we don't try
+			// to exclude them.
+			switch filepath.Base(filePath) {
+			case ".bzr", ".git", ".hg", ".svn":
+				return filepath.SkipDir
+			}
+
 			// Skip some subdirectories inside vendor, but maintain bug
 			// golang.org/issue/31562, described in isVendoredPackage.
 			// We would like Create and CreateFromDir to produce the same result
diff --git a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/asmdecl/asmdecl.go b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/asmdecl/asmdecl.go
index c2e89ee2dc..5c93a4f703 100644
--- a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/asmdecl/asmdecl.go
+++ b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/asmdecl/asmdecl.go
@@ -22,9 +22,11 @@ import (
 	"golang.org/x/tools/go/analysis/passes/internal/analysisutil"
 )
 
+const Doc = "report mismatches between assembly files and Go declarations"
+
 var Analyzer = &analysis.Analyzer{
 	Name: "asmdecl",
-	Doc:  "report mismatches between assembly files and Go declarations",
+	Doc:  Doc,
 	Run:  run,
 }
 
diff --git a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/bools/bools.go b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/bools/bools.go
index fbc1f7ea91..5ae47d8948 100644
--- a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/bools/bools.go
+++ b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/bools/bools.go
@@ -17,9 +17,11 @@ import (
 	"golang.org/x/tools/go/ast/inspector"
 )
 
+const Doc = "check for common mistakes involving boolean operators"
+
 var Analyzer = &analysis.Analyzer{
 	Name:     "bools",
-	Doc:      "check for common mistakes involving boolean operators",
+	Doc:      Doc,
 	Requires: []*analysis.Analyzer{inspect.Analyzer},
 	Run:      run,
 }
diff --git a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/buildtag/buildtag.go b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/buildtag/buildtag.go
index 5a441e609b..78176f1011 100644
--- a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/buildtag/buildtag.go
+++ b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/buildtag/buildtag.go
@@ -16,9 +16,11 @@ import (
 	"golang.org/x/tools/go/analysis/passes/internal/analysisutil"
 )
 
+const Doc = "check that +build tags are well-formed and correctly located"
+
 var Analyzer = &analysis.Analyzer{
 	Name: "buildtag",
-	Doc:  "check that +build tags are well-formed and correctly located",
+	Doc:  Doc,
 	Run:  runBuildTag,
 }
 
diff --git a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/cgocall/cgocall.go b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/cgocall/cgocall.go
index d499f3c329..1b7b8d2de7 100644
--- a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/cgocall/cgocall.go
+++ b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/cgocall/cgocall.go
@@ -23,7 +23,7 @@ import (
 
 const debug = false
 
-const doc = `detect some violations of the cgo pointer passing rules
+const Doc = `detect some violations of the cgo pointer passing rules
 
 Check for invalid cgo pointer passing.
 This looks for code that uses cgo to call C code passing values
@@ -34,7 +34,7 @@ or slice to C, either directly, or via a pointer, array, or struct.`
 
 var Analyzer = &analysis.Analyzer{
 	Name:             "cgocall",
-	Doc:              doc,
+	Doc:              Doc,
 	RunDespiteErrors: true,
 	Run:              run,
 }
diff --git a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/errorsas/errorsas.go b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/errorsas/errorsas.go
index cd37407144..b80271afb9 100644
--- a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/errorsas/errorsas.go
+++ b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/errorsas/errorsas.go
@@ -16,14 +16,14 @@ import (
 	"golang.org/x/tools/go/types/typeutil"
 )
 
-const doc = `report passing non-pointer or non-error values to errors.As
+const Doc = `report passing non-pointer or non-error values to errors.As
 
 The errorsas analysis reports calls to errors.As where the type
 of the second argument is not a pointer to a type implementing error.`
 
 var Analyzer = &analysis.Analyzer{
 	Name:     "errorsas",
-	Doc:      doc,
+	Doc:      Doc,
 	Requires: []*analysis.Analyzer{inspect.Analyzer},
 	Run:      run,
 }
diff --git a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/lostcancel/lostcancel.go b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/lostcancel/lostcancel.go
index 85e7ba7a8e..de6f840f68 100644
--- a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/lostcancel/lostcancel.go
+++ b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/lostcancel/lostcancel.go
@@ -3,7 +3,7 @@
 // license that can be found in the LICENSE file.
 
 // Package lostcancel defines an Analyzer that checks for failure to
-// call a context cancelation function.
+// call a context cancellation function.
 package lostcancel
 
 import (
@@ -20,7 +20,7 @@ import (
 
 const Doc = `check cancel func returned by context.WithCancel is called
 
-The cancelation function returned by context.WithCancel, WithTimeout,
+The cancellation function returned by context.WithCancel, WithTimeout,
 and WithDeadline must be called or the new context will remain live
 until its parent context is cancelled.
 (The background context is never cancelled.)`
diff --git a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/printf/printf.go b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/printf/printf.go
index 38a752c957..a81dba9125 100644
--- a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/printf/printf.go
+++ b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/printf/printf.go
@@ -33,14 +33,14 @@ func init() {
 
 var Analyzer = &analysis.Analyzer{
 	Name:       "printf",
-	Doc:        doc,
+	Doc:        Doc,
 	Requires:   []*analysis.Analyzer{inspect.Analyzer},
 	Run:        run,
 	ResultType: reflect.TypeOf((*Result)(nil)),
 	FactTypes:  []analysis.Fact{new(isWrapper)},
 }
 
-const doc = `check consistency of Printf format strings and arguments
+const Doc = `check consistency of Printf format strings and arguments
 
 The check applies to known functions (for example, those in package fmt)
 as well as any detected wrappers of known functions.
diff --git a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/shift/shift.go b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/shift/shift.go
index 0db95dafb0..1f3df07ccd 100644
--- a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/shift/shift.go
+++ b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/shift/shift.go
@@ -21,9 +21,11 @@ import (
 	"golang.org/x/tools/go/ast/inspector"
 )
 
+const Doc = "check for shifts that equal or exceed the width of the integer"
+
 var Analyzer = &analysis.Analyzer{
 	Name:     "shift",
-	Doc:      "check for shifts that equal or exceed the width of the integer",
+	Doc:      Doc,
 	Requires: []*analysis.Analyzer{inspect.Analyzer},
 	Run:      run,
 }
diff --git a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/unmarshal/unmarshal.go b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/unmarshal/unmarshal.go
index d019ecef15..f9cc993cbb 100644
--- a/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/unmarshal/unmarshal.go
+++ b/src/cmd/vendor/golang.org/x/tools/go/analysis/passes/unmarshal/unmarshal.go
@@ -16,14 +16,14 @@ import (
 	"golang.org/x/tools/go/types/typeutil"
 )
 
-const doc = `report passing non-pointer or non-interface values to unmarshal
+const Doc = `report passing non-pointer or non-interface values to unmarshal
 
 The unmarshal analysis reports calls to functions such as json.Unmarshal
 in which the argument type is not a pointer or an interface.`
 
 var Analyzer = &analysis.Analyzer{
 	Name:     "unmarshal",
-	Doc:      doc,
+	Doc:      Doc,
 	Requires: []*analysis.Analyzer{inspect.Analyzer},
 	Run:      run,
 }
diff --git a/src/cmd/vendor/modules.txt b/src/cmd/vendor/modules.txt
index e1a880c677..757a4c3793 100644
--- a/src/cmd/vendor/modules.txt
+++ b/src/cmd/vendor/modules.txt
@@ -29,7 +29,7 @@ golang.org/x/arch/x86/x86asm
 golang.org/x/crypto/ed25519
 golang.org/x/crypto/ed25519/internal/edwards25519
 golang.org/x/crypto/ssh/terminal
-# golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee
+# golang.org/x/mod v0.1.1-0.20191126161957-788aebd06792
 ## explicit
 golang.org/x/mod/internal/lazyregexp
 golang.org/x/mod/modfile
@@ -44,7 +44,7 @@ golang.org/x/mod/zip
 ## explicit
 golang.org/x/sys/unix
 golang.org/x/sys/windows
-# golang.org/x/tools v0.0.0-20191104222624-6b7b8b79ae80
+# golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e
 ## explicit
 golang.org/x/tools/go/analysis
 golang.org/x/tools/go/analysis/internal/analysisflags