Treat incomplete remote tag observations as uncertain

internal/git/remote.go

@@ -43,7 +43,7 @@ const (
 )
 
 // RemoteRef holds an exact ref's object and optional peeled commit. State is
-// RefConflict only when more than one exact result or malformed data is found.
+// RefConflict when records are inconsistent or incomplete.
 type RemoteRef struct {
 	State  RefState
 	Object string
@@ -130,7 +130,7 @@ func (endpoint Endpoint) Query(ctx context.Context, repositoryDir, tag string) (
 			remoteTag = mergeRef(remoteTag, object, true)
 		}
 	}
-	return Snapshot{Main: main, Tag: remoteTag}, nil
+	return Snapshot{Main: main, Tag: finalizeRef(remoteTag)}, nil
 }
 
 // RequireCandidate requires exact main equality and an absent remote
@@ -294,6 +294,13 @@ func mergeRef(ref RemoteRef, object string, peeled bool) RemoteRef {
 	return ref
 }
 
+func finalizeRef(ref RemoteRef) RemoteRef {
+	if ref.State == RefPresent && ref.Object == "" && ref.Peeled != "" {
+		ref.State = RefConflict
+	}
+	return ref
+}
+
 func checkTagRef(ctx context.Context, repositoryDir, tag string) error {
 	if tag == "" {
 		return fmt.Errorf("invalid Git tag name %q", tag)