fix #19545 (#19563)

modules/repository/repo.go

@@ -93,7 +93,7 @@ func MigrateRepositoryGitData(ctx context.Context, u *user_model.User,
 				return repo, fmt.Errorf("Failed to remove %s: %v", wikiPath, err)
 			}
 
-			if err = git.Clone(ctx, wikiRemotePath, wikiPath, git.CloneRepoOptions{
+			if err := git.Clone(ctx, wikiRemotePath, wikiPath, git.CloneRepoOptions{
 				Mirror:        true,
 				Quiet:         true,
 				Timeout:       migrateTimeout,
@@ -104,12 +104,13 @@ func MigrateRepositoryGitData(ctx context.Context, u *user_model.User,
 				if err := util.RemoveAll(wikiPath); err != nil {
 					return repo, fmt.Errorf("Failed to remove %s: %v", wikiPath, err)
 				}
-			}
-		}
+			} else {
 				if err := git.WriteCommitGraph(ctx, wikiPath); err != nil {
 					return repo, err
 				}
 			}
+		}
+	}
 
 	if repo.OwnerID == u.ID {
 		repo.Owner = u