// returning either a new origin or one of its unmodified arguments.
// If the two origins conflict including if either is nil,
// mergeOrigin returns nil.
func mergeOrigin(m1, m2 *codehost.Origin) *codehost.Origin {
	if m1 == nil || m2 == nil {
		return nil
	}

	if m2.VCS != m1.VCS ||
		m2.URL != m1.URL ||
		m2.Subdir != m1.Subdir {
		return nil
	}

	merged := *m1

import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"os"
	"runtime"
	"strings"

	"cmd/go/internal/base"
	"cmd/go/internal/cfg"
	"cmd/go/internal/gover"
	"cmd/go/internal/modfetch/codehost"
	"cmd/go/internal/modinfo"
	"cmd/go/internal/search"
	"cmd/internal/pkgpattern"

	"golang.org/x/mod/module"
)

type ListMode int

const (
	ListU ListMode = 1 << iota
	ListRetracted

// Copyright 2019 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 codehost

import (
	"archive/zip"
	"context"
	"encoding/xml"
	"fmt"
	"io"
	"os"
	"path"
	"path/filepath"
	"strconv"
	"time"

	"cmd/go/internal/base"
)

func svnParseStat(rev, out string) (*RevInfo, error) {
	var log struct {
		Logentry struct {

func checkReuse(ctx context.Context, m module.Version, old *codehost.Origin) error {
	return modfetch.TryProxies(func(proxy string) error {
		repo, err := lookupRepo(ctx, proxy, m.Path)
		if err != nil {
			return err
		}
		return checkReuseRepo(ctx, repo, m.Path, m.Version, old)
	})
}

func checkReuseRepo(ctx context.Context, repo versionRepo, path, query string, origin *codehost.Origin) error {
	if origin == nil {

	"errors"
	"flag"
	"fmt"
	"internal/txtar"
	"io"
	"io/fs"
	"log"
	"net"
	"net/http"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"sync"
	"testing"

	"cmd/go/internal/modfetch/codehost"
	"cmd/go/internal/par"

	"golang.org/x/mod/module"
	"golang.org/x/mod/semver"
	"golang.org/x/mod/sumdb"
	"golang.org/x/mod/sumdb/dirhash"
)

var (

import (
	"context"
	"encoding/json"
	"errors"
	"os"
	"runtime"
	"sync"

	"cmd/go/internal/base"
	"cmd/go/internal/cfg"
	"cmd/go/internal/gover"
	"cmd/go/internal/modfetch"
	"cmd/go/internal/modfetch/codehost"
	"cmd/go/internal/modload"
	"cmd/go/internal/toolchain"

	"golang.org/x/mod/module"
)

var cmdDownload = &base.Command{
	UsageLine: "go mod download [-x] [-json] [-reuse=old.json] [modules]",

	"math/rand"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"sync"

	"cmd/go/internal/base"
	"cmd/go/internal/cfg"
	"cmd/go/internal/gover"
	"cmd/go/internal/lockedfile"
	"cmd/go/internal/modfetch/codehost"
	"cmd/go/internal/par"
	"cmd/go/internal/robustio"
	"cmd/internal/telemetry"

	"golang.org/x/mod/module"
	"golang.org/x/mod/semver"
)

func cacheDir(ctx context.Context, path string) (string, error) {

	// the Go command does, which is beneficial.
	//
	// Note: some of this code copied from https://go.googlesource.com/go/+/refs/tags/go1.16.5/src/cmd/go/internal/modfetch/codehost/git.go#826.
	cmd := exec.Command("git", "-c", "core.autocrlf=input", "-c", "core.eol=lf", "archive", "--format=zip", rev)
	if subdir != "" {
		cmd.Args = append(cmd.Args, subdir)
	}
	cmd.Dir = dir

// Copyright 2018 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 codehost

import (
	"archive/zip"
	"bytes"
	"cmd/go/internal/cfg"
	"cmd/go/internal/vcweb/vcstest"
	"context"
	"flag"
	"internal/testenv"
	"io"
	"io/fs"
	"log"
	"os"
	"path"
	"path/filepath"
	"reflect"
	"runtime"
	"strings"
	"sync"

// Copyright 2018 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 codehost

import (
	"context"
	"errors"
	"fmt"
	"internal/lazyregexp"
	"io"
	"io/fs"
	"os"
	"path/filepath"
	"sort"
	"strconv"
	"strings"
	"sync"
	"time"

	"cmd/go/internal/base"
	"cmd/go/internal/lockedfile"
	"cmd/go/internal/par"