cmd/go/internal/modfetch/codehost: ignore incomplete semver tags in RecentTag

Fixes #31965

Change-Id: I2126903196b630c0bee2c022be1a818e0856ce3b
Reviewed-on: https://go-review.googlesource.com/c/go/+/176539
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

diff --git a/src/cmd/go/internal/modfetch/codehost/git.go b/src/cmd/go/internal/modfetch/codehost/git.go
index 55627cb72ac7041183adfb432643fc4f4ae3e3ca..272eadcb233cb83104e5230515757c9b80f1ab87 100644 (file)
--- a/src/cmd/go/internal/modfetch/codehost/git.go
+++ b/src/cmd/go/internal/modfetch/codehost/git.go
@@ -678,7 +678,8 @@ func (r *gitRepo) RecentTag(rev, prefix string) (tag string, err error) {
                        }
 
                        semtag := line[len(prefix):]
-                       if semver.IsValid(semtag) {
+                       // Consider only tags that are valid and complete (not just major.minor prefixes).
+                       if c := semver.Canonical(semtag); c != "" && strings.HasPrefix(semtag, c) {
                                highest = semver.Max(highest, semtag)
                        }
                }