1 files changed, 154 insertions, 0 deletions
diff --git a/libgo/go/cmd/go/internal/modfetch/codehost/svn.go b/libgo/go/cmd/go/internal/modfetch/codehost/svn.go
new file mode 100644
index 00000000000..6ec9e59c9c6
--- /dev/null
+++ b/libgo/go/cmd/go/internal/modfetch/codehost/svn.go
@@ -0,0 +1,154 @@
+// 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"
+	"encoding/xml"
+	"fmt"
+	"io"
+	"os"
+	"path"
+	"path/filepath"
+	"time"
+)
+
+func svnParseStat(rev, out string) (*RevInfo, error) {
+	var log struct {
+		Logentry struct {
+			Revision int64  `xml:"revision,attr"`
+			Date     string `xml:"date"`
+		} `xml:"logentry"`
+	}
+	if err := xml.Unmarshal([]byte(out), &log); err != nil {
+		return nil, vcsErrorf("unexpected response from svn log --xml: %v\n%s", err, out)
+	}
+
+	t, err := time.Parse(time.RFC3339, log.Logentry.Date)
+	if err != nil {
+		return nil, vcsErrorf("unexpected response from svn log --xml: %v\n%s", err, out)
+	}
+
+	info := &RevInfo{
+		Name:    fmt.Sprintf("%d", log.Logentry.Revision),
+		Short:   fmt.Sprintf("%012d", log.Logentry.Revision),
+		Time:    t.UTC(),
+		Version: rev,
+	}
+	return info, nil
+}
+
+func svnReadZip(dst io.Writer, workDir, rev, subdir, remote string) (err error) {
+	// The subversion CLI doesn't provide a command to write the repository
+	// directly to an archive, so we need to export it to the local filesystem
+	// instead. Unfortunately, the local filesystem might apply arbitrary
+	// normalization to the filenames, so we need to obtain those directly.
+	//
+	// 'svn export' prints the filenames as they are written, but from reading the
+	// svn source code (as of revision 1868933), those filenames are encoded using
+	// the system locale rather than preserved byte-for-byte from the origin. For
+	// our purposes, that won't do, but we don't want to go mucking around with
+	// the user's locale settings either — that could impact error messages, and
+	// we don't know what locales the user has available or what LC_* variables
+	// their platform supports.
+	//
+	// Instead, we'll do a two-pass export: first we'll run 'svn list' to get the
+	// canonical filenames, then we'll 'svn export' and look for those filenames
+	// in the local filesystem. (If there is an encoding problem at that point, we
+	// would probably reject the resulting module anyway.)
+
+	remotePath := remote
+	if subdir != "" {
+		remotePath += "/" + subdir
+	}
+
+	out, err := Run(workDir, []string{
+		"svn", "list",
+		"--non-interactive",
+		"--xml",
+		"--incremental",
+		"--recursive",
+		"--revision", rev,
+		"--", remotePath,
+	})
+	if err != nil {
+		return err
+	}
+
+	type listEntry struct {
+		Kind string `xml:"kind,attr"`
+		Name string `xml:"name"`
+		Size int64  `xml:"size"`
+	}
+	var list struct {
+		Entries []listEntry `xml:"entry"`
+	}
+	if err := xml.Unmarshal(out, &list); err != nil {
+		return vcsErrorf("unexpected response from svn list --xml: %v\n%s", err, out)
+	}
+
+	exportDir := filepath.Join(workDir, "export")
+	// Remove any existing contents from a previous (failed) run.
+	if err := os.RemoveAll(exportDir); err != nil {
+		return err
+	}
+	defer os.RemoveAll(exportDir) // best-effort
+
+	_, err = Run(workDir, []string{
+		"svn", "export",
+		"--non-interactive",
+		"--quiet",
+
+		// Suppress any platform- or host-dependent transformations.
+		"--native-eol", "LF",
+		"--ignore-externals",
+		"--ignore-keywords",
+
+		"--revision", rev,
+		"--", remotePath,
+		exportDir,
+	})
+	if err != nil {
+		return err
+	}
+
+	// Scrape the exported files out of the filesystem and encode them in the zipfile.
+
+	// “All files in the zip file are expected to be
+	// nested in a single top-level directory, whose name is not specified.”
+	// We'll (arbitrarily) choose the base of the remote path.
+	basePath := path.Join(path.Base(remote), subdir)
+
+	zw := zip.NewWriter(dst)
+	for _, e := range list.Entries {
+		if e.Kind != "file" {
+			continue
+		}
+
+		zf, err := zw.Create(path.Join(basePath, e.Name))
+		if err != nil {
+			return err
+		}
+
+		f, err := os.Open(filepath.Join(exportDir, e.Name))
+		if err != nil {
+			if os.IsNotExist(err) {
+				return vcsErrorf("file reported by 'svn list', but not written by 'svn export': %s", e.Name)
+			}
+			return fmt.Errorf("error opening file created by 'svn export': %v", err)
+		}
+
+		n, err := io.Copy(zf, f)
+		f.Close()
+		if err != nil {
+			return err
+		}
+		if n != e.Size {
+			return vcsErrorf("file size differs between 'svn list' and 'svn export': file %s listed as %v bytes, but exported as %v bytes", e.Name, e.Size, n)
+		}
+	}
+
+	return zw.Close()
+}