tpl: Sync go_templates for Go 1.18

Using Go tag go1.18 4aa1efed4853ea067d665a952eee77c52faac774

Updates #9677

47 files changed, 695 insertions, 220 deletions

diff --git a/tpl/internal/go_templates/cfg/cfg.go b/tpl/internal/go_templates/cfg/cfg.go
index 553021374..78664d7a9 100644
--- a/tpl/internal/go_templates/cfg/cfg.go
+++ b/tpl/internal/go_templates/cfg/cfg.go
@@ -33,12 +33,14 @@ const KnownEnv = `
 	GCCGO
 	GO111MODULE
 	GO386
+	GOAMD64
 	GOARCH
 	GOARM
 	GOBIN
 	GOCACHE
 	GOENV
 	GOEXE
+	GOEXPERIMENT
 	GOFLAGS
 	GOGCCFLAGS
 	GOHOSTARCH
@@ -60,6 +62,7 @@ const KnownEnv = `
 	GOTOOLDIR
 	GOVCS
 	GOWASM
+	GOWORK
 	GO_EXTLINK_ENABLED
 	PKG_CONFIG
 `
diff --git a/tpl/internal/go_templates/fmtsort/sort.go b/tpl/internal/go_templates/fmtsort/sort.go
index 7127ba6ac..34c1f477f 100644
--- a/tpl/internal/go_templates/fmtsort/sort.go
+++ b/tpl/internal/go_templates/fmtsort/sort.go
@@ -130,7 +130,7 @@ func compare(aVal, bVal reflect.Value) int {
 		default:
 			return -1
 		}
-	case reflect.Ptr, reflect.UnsafePointer:
+	case reflect.Pointer, reflect.UnsafePointer:
 		a, b := aVal.Pointer(), bVal.Pointer()
 		switch {
 		case a < b:
diff --git a/tpl/internal/go_templates/fmtsort/sort_test.go b/tpl/internal/go_templates/fmtsort/sort_test.go
index 5205a6413..a05e8a3c3 100644
--- a/tpl/internal/go_templates/fmtsort/sort_test.go
+++ b/tpl/internal/go_templates/fmtsort/sort_test.go
@@ -9,6 +9,7 @@ import (
 	"github.com/gohugoio/hugo/tpl/internal/go_templates/fmtsort"
 	"math"
 	"reflect"
+	"sort"
 	"strings"
 	"testing"
 	"unsafe"
@@ -37,12 +38,12 @@ var compareTests = [][]reflect.Value{
 	ct(reflect.TypeOf(chans[0]), chans[0], chans[1], chans[2]),
 	ct(reflect.TypeOf(toy{}), toy{0, 1}, toy{0, 2}, toy{1, -1}, toy{1, 1}),
 	ct(reflect.TypeOf([2]int{}), [2]int{1, 1}, [2]int{1, 2}, [2]int{2, 0}),
-	ct(reflect.TypeOf(interface{}(interface{}(0))), iFace, 1, 2, 3),
+	ct(reflect.TypeOf(any(any(0))), iFace, 1, 2, 3),
 }
 
-var iFace interface{}
+var iFace any
 
-func ct(typ reflect.Type, args ...interface{}) []reflect.Value {
+func ct(typ reflect.Type, args ...any) []reflect.Value {
 	value := make([]reflect.Value, len(args))
 	for i, v := range args {
 		x := reflect.ValueOf(v)
@@ -83,8 +84,8 @@ func TestCompare(t *testing.T) {
 }
 
 type sortTest struct {
-	data  interface{} // Always a map.
-	print string      // Printed result using our custom printer.
+	data  any    // Always a map.
+	print string // Printed result using our custom printer.
 }
 
 var sortTests = []sortTest{
@@ -134,7 +135,7 @@ var sortTests = []sortTest{
 	},
 }
 
-func sprint(data interface{}) string {
+func sprint(data any) string {
 	om := fmtsort.Sort(reflect.ValueOf(data))
 	if om == nil {
 		return "nil"
@@ -188,9 +189,19 @@ func sprintKey(key reflect.Value) string {
 
 var (
 	ints  [3]int
-	chans = [3]chan int{make(chan int), make(chan int), make(chan int)}
+	chans = makeChans()
 )
 
+func makeChans() []chan int {
+	cs := []chan int{make(chan int), make(chan int), make(chan int)}
+	// Order channels by address. See issue #49431.
+	// TODO: pin these pointers once pinning is available (#46787).
+	sort.Slice(cs, func(i, j int) bool {
+		return uintptr(reflect.ValueOf(cs[i]).UnsafePointer()) < uintptr(reflect.ValueOf(cs[j]).UnsafePointer())
+	})
+	return cs
+}
+
 func pointerMap() map[*int]string {
 	m := make(map[*int]string)
 	for i := 2; i >= 0; i-- {
@@ -233,7 +244,7 @@ func TestInterface(t *testing.T) {
 	// A map containing multiple concrete types should be sorted by type,
 	// then value. However, the relative ordering of types is unspecified,
 	// so test this by checking the presence of sorted subgroups.
-	m := map[interface{}]string{
+	m := map[any]string{
 		[2]int{1, 0}:             "",
 		[2]int{0, 1}:             "",
 		true:                     "",
diff --git a/tpl/internal/go_templates/htmltemplate/attr.go b/tpl/internal/go_templates/htmltemplate/attr.go
index 22922e603..6c52211fe 100644
--- a/tpl/internal/go_templates/htmltemplate/attr.go
+++ b/tpl/internal/go_templates/htmltemplate/attr.go
@@ -143,12 +143,12 @@ func attrType(name string) contentType {
 		// widely applied.
 		// Treat data-action as URL below.
 		name = name[5:]
-	} else if colon := strings.IndexRune(name, ':'); colon != -1 {
-		if name[:colon] == "xmlns" {
+	} else if prefix, short, ok := strings.Cut(name, ":"); ok {
+		if prefix == "xmlns" {
 			return contentTypeURL
 		}
 		// Treat svg:href and xlink:href as href below.
-		name = name[colon+1:]
+		name = short
 	}
 	if t, ok := attrTypeMap[name]; ok {
 		return t
diff --git a/tpl/internal/go_templates/htmltemplate/clone_test.go b/tpl/internal/go_templates/htmltemplate/clone_test.go
index 7c774e923..553f656b5 100644
--- a/tpl/internal/go_templates/htmltemplate/clone_test.go
+++ b/tpl/internal/go_templates/htmltemplate/clone_test.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build go1.13 && !windows
 // +build go1.13,!windows
 
 package template
diff --git a/tpl/internal/go_templates/htmltemplate/content.go b/tpl/internal/go_templates/htmltemplate/content.go
index bc32dc813..65cc3086c 100644
--- a/tpl/internal/go_templates/htmltemplate/content.go
+++ b/tpl/internal/go_templates/htmltemplate/content.go
@@ -29,16 +29,16 @@ const (
 
 // indirect returns the value, after dereferencing as many times
 // as necessary to reach the base type (or nil).
-func indirect(a interface{}) interface{} {
+func indirect(a any) any {
 	if a == nil {
 		return nil
 	}
-	if t := reflect.TypeOf(a); t.Kind() != reflect.Ptr {
+	if t := reflect.TypeOf(a); t.Kind() != reflect.Pointer {
 		// Avoid creating a reflect.Value if it's not a pointer.
 		return a
 	}
 	v := reflect.ValueOf(a)
-	for v.Kind() == reflect.Ptr && !v.IsNil() {
+	for v.Kind() == reflect.Pointer && !v.IsNil() {
 		v = v.Elem()
 	}
 	return v.Interface()
@@ -52,12 +52,12 @@ var (
 // indirectToStringerOrError returns the value, after dereferencing as many times
 // as necessary to reach the base type (or nil) or an implementation of fmt.Stringer
 // or error,
-func indirectToStringerOrError(a interface{}) interface{} {
+func indirectToStringerOrError(a any) any {
 	if a == nil {
 		return nil
 	}
 	v := reflect.ValueOf(a)
-	for !v.Type().Implements(fmtStringerType) && !v.Type().Implements(errorType) && v.Kind() == reflect.Ptr && !v.IsNil() {
+	for !v.Type().Implements(fmtStringerType) && !v.Type().Implements(errorType) && v.Kind() == reflect.Pointer && !v.IsNil() {
 		v = v.Elem()
 	}
 	return v.Interface()
@@ -65,7 +65,7 @@ func indirectToStringerOrError(a interface{}) interface{} {
 
 // stringify converts its arguments to a string and the type of the content.
 // All pointers are dereferenced, as in the text/template package.
-func stringify(args ...interface{}) (string, contentType) {
+func stringify(args ...any) (string, contentType) {
 	if len(args) == 1 {
 		switch s := indirect(args[0]).(type) {
 		case string:
diff --git a/tpl/internal/go_templates/htmltemplate/content_test.go b/tpl/internal/go_templates/htmltemplate/content_test.go
index 909a24bc0..29221a4ad 100644
--- a/tpl/internal/go_templates/htmltemplate/content_test.go
+++ b/tpl/internal/go_templates/htmltemplate/content_test.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build go1.13 && !windows
 // +build go1.13,!windows
 
 package template
@@ -15,7 +16,7 @@ import (
 )
 
 func TestTypedContent(t *testing.T) {
-	data := []interface{}{
+	data := []any{
 		`<b> "foo%" O'Reilly &bar;`,
 		htmltemplate.CSS(`a[href =~ "//example.com"]#foo`),
 		htmltemplate.HTML(`Hello, <b>World</b> &amp;tc!`),
@@ -452,7 +453,7 @@ func TestEscapingNilNonemptyInterfaces(t *testing.T) {
 
 	// A non-empty interface should print like an empty interface.
 	want := new(bytes.Buffer)
-	data := struct{ E interface{} }{}
+	data := struct{ E any }{}
 	tmpl.Execute(want, data)
 
 	if !bytes.Equal(want.Bytes(), got.Bytes()) {
diff --git a/tpl/internal/go_templates/htmltemplate/context.go b/tpl/internal/go_templates/htmltemplate/context.go
index 006b870ec..c28e08dce 100644
--- a/tpl/internal/go_templates/htmltemplate/context.go
+++ b/tpl/internal/go_templates/htmltemplate/context.go
@@ -4,7 +4,11 @@
 
 package template
 
-import "fmt"
+import (
+	"fmt"
+
+	"github.com/gohugoio/hugo/tpl/internal/go_templates/texttemplate/parse"
+)
 
 // context describes the state an HTML parser must be in when it reaches the
 // portion of HTML produced by evaluating a particular template node.
@@ -20,6 +24,7 @@ type context struct {
 	jsCtx   jsCtx
 	attr    attr
 	element element
+	n       parse.Node // for range break/continue
 	err     *Error
 }
 
@@ -139,6 +144,8 @@ const (
 	// stateError is an infectious error state outside any valid
 	// HTML/CSS/JS construct.
 	stateError
+	// stateDead marks unreachable code after a {{break}} or {{continue}}.
+	stateDead
 )
 
 // isComment is true for any state that contains content meant for template
diff --git a/tpl/internal/go_templates/htmltemplate/css.go b/tpl/internal/go_templates/htmltemplate/css.go
index eb92fc92b..890a0c6b2 100644
--- a/tpl/internal/go_templates/htmltemplate/css.go
+++ b/tpl/internal/go_templates/htmltemplate/css.go
@@ -155,7 +155,7 @@ func isCSSSpace(b byte) bool {
 }
 
 // cssEscaper escapes HTML and CSS special characters using \<hex>+ escapes.
-func cssEscaper(args ...interface{}) string {
+func cssEscaper(args ...any) string {
 	s, _ := stringify(args...)
 	var b strings.Builder
 	r, w, written := rune(0), 0, 0
@@ -218,7 +218,7 @@ var mozBindingBytes = []byte("mozbinding")
 // (inherit, blue), and colors (#888).
 // It filters out unsafe values, such as those that affect token boundaries,
 // and anything that might execute scripts.
-func cssValueFilter(args ...interface{}) string {
+func cssValueFilter(args ...any) string {
 	s, t := stringify(args...)
 	if t == contentTypeCSS {
 		return s
diff --git a/tpl/internal/go_templates/htmltemplate/css_test.go b/tpl/internal/go_templates/htmltemplate/css_test.go
index afed58c29..7d8ad8b59 100644
--- a/tpl/internal/go_templates/htmltemplate/css_test.go
+++ b/tpl/internal/go_templates/htmltemplate/css_test.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build go1.13 && !windows
 // +build go1.13,!windows
 
 package template
diff --git a/tpl/internal/go_templates/htmltemplate/error.go b/tpl/internal/go_templates/htmltemplate/error.go
index f8b3f1cea..21c86a9ef 100644
--- a/tpl/internal/go_templates/htmltemplate/error.go
+++ b/tpl/internal/go_templates/htmltemplate/error.go
@@ -229,6 +229,6 @@ func (e *Error) Error() string {
 
 // errorf creates an error given a format string f and args.
 // The template Name still needs to be supplied.
-func errorf(k ErrorCode, node parse.Node, line int, f string, args ...interface{}) *Error {
+func errorf(k ErrorCode, node parse.Node, line int, f string, args ...any) *Error {
 	return &Error{k, node, "", line, fmt.Sprintf(f, args...)}
 }
diff --git a/tpl/internal/go_templates/htmltemplate/escape.go b/tpl/internal/go_templates/htmltemplate/escape.go
index 5f4c92a17..5382c4288 100644
--- a/tpl/internal/go_templates/htmltemplate/escape.go
+++ b/tpl/internal/go_templates/htmltemplate/escape.go
@@ -46,7 +46,7 @@ func escapeTemplate(tmpl *Template, node parse.Node, name string) error {
 
 // evalArgs formats the list of arguments into a string. It is equivalent to
 // fmt.Sprint(args...), except that it deferences all pointers.
-func evalArgs(args ...interface{}) string {
+func evalArgs(args ...any) string {
 	// Optimization for simple common case of a single string argument.
 	if len(args) == 1 {
 		if s, ok := args[0].(string); ok {
@@ -98,6 +98,15 @@ type escaper struct {
 	actionNodeEdits   map[*parse.ActionNode][]string
 	templateNodeEdits map[*parse.TemplateNode]string
 	textNodeEdits     map[*parse.TextNode][]byte
+	// rangeContext holds context about the current range loop.
+	rangeContext *rangeContext
+}
+
+// rangeContext holds information about the current range loop.
+type rangeContext struct {
+	outer     *rangeContext // outer loop
+	breaks    []context     // context at each break action
+	continues []context     // context at each continue action
 }
 
 // makeEscaper creates a blank escaper for the given set.
@@ -110,6 +119,7 @@ func makeEscaper(n *nameSpace) escaper {
 		map[*parse.ActionNode][]string{},
 		map[*parse.TemplateNode]string{},
 		map[*parse.TextNode][]byte{},
+		nil,
 	}
 }
 
@@ -125,8 +135,16 @@ func (e *escaper) escape(c context, n parse.Node) context {
 	switch n := n.(type) {
 	case *parse.ActionNode:
 		return e.escapeAction(c, n)
+	case *parse.BreakNode:
+		c.n = n
+		e.rangeContext.breaks = append(e.rangeContext.breaks, c)
+		return context{state: stateDead}
 	case *parse.CommentNode:
 		return c
+	case *parse.ContinueNode:
+		c.n = n
+		e.rangeContext.continues = append(e.rangeContext.breaks, c)
+		return context{state: stateDead}
 	case *parse.IfNode:
 		return e.escapeBranch(c, &n.BranchNode, "if")
 	case *parse.ListNode:
@@ -428,6 +446,12 @@ func join(a, b context, node parse.Node, nodeName string) context {
 	if b.state == stateError {
 		return b
 	}
+	if a.state == stateDead {
+		return b
+	}
+	if b.state == stateDead {
+		return a
+	}
 	if a.eq(b) {
 		return a
 	}
@@ -467,14 +491,27 @@ func join(a, b context, node parse.Node, nodeName string) context {
 
 // escapeBranch escapes a branch template node: "if", "range" and "with".
 func (e *escaper) escapeBranch(c context, n *parse.BranchNode, nodeName string) context {
+	if nodeName == "range" {
+		e.rangeContext = &rangeContext{outer: e.rangeContext}
+	}
 	c0 := e.escapeList(c, n.List)
-	if nodeName == "range" && c0.state != stateError {
+	if nodeName == "range" {
+		if c0.state != stateError {
+			c0 = joinRange(c0, e.rangeContext)
+		}
+		e.rangeContext = e.rangeContext.outer
+		if c0.state == stateError {
+			return c0
+		}
+
 		// The "true" branch of a "range" node can execute multiple times.
 		// We check that executing n.List once results in the same context
 		// as executing n.List twice.
+		e.rangeContext = &rangeContext{outer: e.rangeContext}
 		c1, _ := e.escapeListConditionally(c0, n.List, nil)
 		c0 = join(c0, c1, n, nodeName)
 		if c0.state == stateError {
+			e.rangeContext = e.rangeContext.outer
 			// Make clear that this is a problem on loop re-entry
 			// since developers tend to overlook that branch when
 			// debugging templates.
@@ -482,11 +519,39 @@ func (e *escaper) escapeBranch(c context, n *parse.BranchNode, nodeName string)
 			c0.err.Description = "on range loop re-entry: " + c0.err.Description
 			return c0
 		}
+		c0 = joinRange(c0, e.rangeContext)
+		e.rangeContext = e.rangeContext.outer
+		if c0.state == stateError {
+			return c0
+		}
 	}
 	c1 := e.escapeList(c, n.ElseList)
 	return join(c0, c1, n, nodeName)
 }
 
+func joinRange(c0 context, rc *rangeContext) context {
+	// Merge contexts at break and continue statements into overall body context.
+	// In theory we could treat breaks differently from continues, but for now it is
+	// enough to treat them both as going back to the start of the loop (which may then stop).
+	for _, c := range rc.breaks {
+		c0 = join(c0, c, c.n, "range")
+		if c0.state == stateError {
+			c0.err.Line = c.n.(*parse.BreakNode).Line
+			c0.err.Description = "at range loop break: " + c0.err.Description
+			return c0
+		}
+	}
+	for _, c := range rc.