1 files changed, 78 insertions, 9 deletions

diff --git a/src/cmd/go/internal/modfetch/coderepo.go b/src/cmd/go/internal/modfetch/coderepo.go
index d043903336..b6bcf83f1a 100644
--- a/src/cmd/go/internal/modfetch/coderepo.go
+++ b/src/cmd/go/internal/modfetch/coderepo.go
@@ -10,6 +10,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"io/fs"
 	"io/ioutil"
 	"os"
 	"path"
@@ -419,9 +420,14 @@ func (r *codeRepo) convert(info *codehost.RevInfo, statVers string) (*RevInfo, e
 		tagPrefix = r.codeDir + "/"
 	}
 
+	isRetracted, err := r.retractedVersions()
+	if err != nil {
+		isRetracted = func(string) bool { return false }
+	}
+
 	// tagToVersion returns the version obtained by trimming tagPrefix from tag.
-	// If the tag is invalid or a pseudo-version, tagToVersion returns an empty
-	// version.
+	// If the tag is invalid, retracted, or a pseudo-version, tagToVersion returns
+	// an empty version.
 	tagToVersion := func(tag string) (v string, tagIsCanonical bool) {
 		if !strings.HasPrefix(tag, tagPrefix) {
 			return "", false
@@ -436,6 +442,9 @@ func (r *codeRepo) convert(info *codehost.RevInfo, statVers string) (*RevInfo, e
 		if v == "" || !strings.HasPrefix(trimmed, v) {
 			return "", false // Invalid or incomplete version (just vX or vX.Y).
 		}
+		if isRetracted(v) {
+			return "", false
+		}
 		if v == trimmed {
 			tagIsCanonical = true
 		}
@@ -500,15 +509,24 @@ func (r *codeRepo) convert(info *codehost.RevInfo, statVers string) (*RevInfo, e
 		return checkGoMod()
 	}
 
+	// Find the highest tagged version in the revision's history, subject to
+	// major version and +incompatible constraints. Use that version as the
+	// pseudo-version base so that the pseudo-version sorts higher. Ignore
+	// retracted versions.
+	allowedMajor := func(major string) func(v string) bool {
+		return func(v string) bool {
+			return (major == "" || semver.Major(v) == major) && !isRetracted(v)
+		}
+	}
 	if pseudoBase == "" {
 		var tag string
 		if r.pseudoMajor != "" || canUseIncompatible() {
-			tag, _ = r.code.RecentTag(info.Name, tagPrefix, r.pseudoMajor)
+			tag, _ = r.code.RecentTag(info.Name, tagPrefix, allowedMajor(r.pseudoMajor))
 		} else {
 			// Allow either v1 or v0, but not incompatible higher versions.
-			tag, _ = r.code.RecentTag(info.Name, tagPrefix, "v1")
+			tag, _ = r.code.RecentTag(info.Name, tagPrefix, allowedMajor("v1"))
 			if tag == "" {
-				tag, _ = r.code.RecentTag(info.Name, tagPrefix, "v0")
+				tag, _ = r.code.RecentTag(info.Name, tagPrefix, allowedMajor("v0"))
 			}
 		}
 		pseudoBase, _ = tagToVersion(tag) // empty if the tag is invalid
@@ -869,6 +887,57 @@ func (r *codeRepo) modPrefix(rev string) string {
 	return r.modPath + "@" + rev
 }
 
+func (r *codeRepo) retractedVersions() (func(string) bool, error) {
+	versions, err := r.Versions("")
+	if err != nil {
+		return nil, err
+	}
+
+	for i, v := range versions {
+		if strings.HasSuffix(v, "+incompatible") {
+			versions = versions[:i]
+			break
+		}
+	}
+	if len(versions) == 0 {
+		return func(string) bool { return false }, nil
+	}
+
+	var highest string
+	for i := len(versions) - 1; i >= 0; i-- {
+		v := versions[i]
+		if semver.Prerelease(v) == "" {
+			highest = v
+			break
+		}
+	}
+	if highest == "" {
+		highest = versions[len(versions)-1]
+	}
+
+	data, err := r.GoMod(highest)
+	if err != nil {
+		return nil, err
+	}
+	f, err := modfile.ParseLax("go.mod", data, nil)
+	if err != nil {
+		return nil, err
+	}
+	retractions := make([]modfile.VersionInterval, len(f.Retract))
+	for _, r := range f.Retract {
+		retractions = append(retractions, r.VersionInterval)
+	}
+
+	return func(v string) bool {
+		for _, r := range retractions {
+			if semver.Compare(r.Low, v) <= 0 && semver.Compare(v, r.High) <= 0 {
+				return true
+			}
+		}
+		return false
+	}, nil
+}
+
 func (r *codeRepo) Zip(dst io.Writer, version string) error {
 	if version != module.CanonicalVersion(version) {
 		return fmt.Errorf("version %s is not canonical", version)
@@ -972,7 +1041,7 @@ type zipFile struct {
 }
 
 func (f zipFile) Path() string                 { return f.name }
-func (f zipFile) Lstat() (os.FileInfo, error)  { return f.f.FileInfo(), nil }
+func (f zipFile) Lstat() (fs.FileInfo, error)  { return f.f.FileInfo(), nil }
 func (f zipFile) Open() (io.ReadCloser, error) { return f.f.Open() }
 
 type dataFile struct {
@@ -981,9 +1050,9 @@ type dataFile struct {
 }
 
 func (f dataFile) Path() string                { return f.name }
-func (f dataFile) Lstat() (os.FileInfo, error) { return dataFileInfo{f}, nil }
+func (f dataFile) Lstat() (fs.FileInfo, error) { return dataFileInfo{f}, nil }
 func (f dataFile) Open() (io.ReadCloser, error) {
-	return ioutil.NopCloser(bytes.NewReader(f.data)), nil
+	return io.NopCloser(bytes.NewReader(f.data)), nil
 }
 
 type dataFileInfo struct {
@@ -992,7 +1061,7 @@ type dataFileInfo struct {
 
 func (fi dataFileInfo) Name() string       { return path.Base(fi.f.name) }
 func (fi dataFileInfo) Size() int64        { return int64(len(fi.f.data)) }
-func (fi dataFileInfo) Mode() os.FileMode  { return 0644 }
+func (fi dataFileInfo) Mode() fs.FileMode  { return 0644 }
 func (fi dataFileInfo) ModTime() time.Time { return time.Time{} }
 func (fi dataFileInfo) IsDir() bool        { return false }
 func (fi dataFileInfo) Sys() interface{}   { return nil }