Re-enable transfer repo back from org to user account (#14807)

* re-enable transfer repo back from org to user account

* add test case

integrations/api_repo_test.go

@@ -450,6 +450,7 @@ func TestAPIRepoTransfer(t *testing.T) {
 		{ctxUserID: 1, newOwner: "user2", teams: &[]int64{2}, expectedStatus: http.StatusUnprocessableEntity},
 		{ctxUserID: 1, newOwner: "user3", teams: &[]int64{5}, expectedStatus: http.StatusForbidden},
 		{ctxUserID: 1, newOwner: "user3", teams: &[]int64{2}, expectedStatus: http.StatusAccepted},
+		{ctxUserID: 2, newOwner: "user2", teams: nil, expectedStatus: http.StatusAccepted},
 	}
 
 	defer prepareTestEnv(t)()

services/repository/transfer.go

@@ -80,8 +80,8 @@ func StartRepositoryTransfer(doer, newOwner *models.User, repo *models.Repositor
 		return fmt.Errorf("repository is not ready for transfer")
 	}
 
-	// Admin is always allowed to transfer
-	if doer.IsAdmin {
+	// Admin is always allowed to transfer || user transfer repo back to his account
+	if doer.IsAdmin || doer.ID == newOwner.ID {
 		return TransferOwnership(doer, newOwner, repo, teams)
 	}