Revert "cmd/go: add a Latest field to the output of 'go mod download -json'"

This reverts CL 183841.

Fixes #34533

Reason for revert: Introduced a significant performance regression for repos with many incompatible-version tags.

Change-Id: I75d7fd76e6e1a0902b114b00167b38439e0f8221
Reviewed-on: https://go-review.googlesource.com/c/go/+/198699
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Katie Hockman <katie@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

1 files changed, 0 insertions, 30 deletions

diff --git a/src/cmd/go/internal/modcmd/download.go b/src/cmd/go/internal/modcmd/download.go
index 60d0d5b6e2..0d432e9549 100644
--- a/src/cmd/go/internal/modcmd/download.go
+++ b/src/cmd/go/internal/modcmd/download.go
@@ -43,7 +43,6 @@ corresponding to this Go struct:
         Dir      string // absolute path to cached source root directory
         Sum      string // checksum for path, version (as in go.sum)
         GoModSum string // checksum for go.mod (as in go.sum)
-        Latest   bool   // would @latest resolve to this version?
     }
 
 See 'go help modules' for more about module queries.
@@ -66,7 +65,6 @@ type moduleJSON struct {
 	Dir      string `json:",omitempty"`
 	Sum      string `json:",omitempty"`
 	GoModSum string `json:",omitempty"`
-	Latest   bool   `json:",omitempty"`
 }
 
 func runDownload(cmd *base.Command, args []string) {
@@ -105,31 +103,6 @@ func runDownload(cmd *base.Command, args []string) {
 		work.Add(m)
 	}
 
-	latest := map[string]string{} // path → version
-	if *downloadJSON {
-		// We need to populate the Latest field, but if the main module depends on a
-		// version newer than latest — or if the version requested on the command
-		// line is itself newer than latest — that's not trivial to determine from
-		// the info returned by ListModules. Instead, we issue a separate
-		// ListModules request for "latest", which should be inexpensive relative to
-		// downloading the modules.
-		var latestArgs []string
-		for _, m := range mods {
-			if m.Error != "" {
-				continue
-			}
-			latestArgs = append(latestArgs, m.Path+"@latest")
-		}
-
-		if len(latestArgs) > 0 {
-			for _, info := range modload.ListModules(latestArgs, listU, listVersions) {
-				if info.Version != "" {
-					latest[info.Path] = info.Version
-				}
-			}
-		}
-	}
-
 	work.Do(10, func(item interface{}) {
 		m := item.(*moduleJSON)
 		var err error
@@ -160,9 +133,6 @@ func runDownload(cmd *base.Command, args []string) {
 			m.Error = err.Error()
 			return
 		}
-		if latest[m.Path] == m.Version {
-			m.Latest = true
-		}
 	})
 
 	if *downloadJSON {