Ensure topics added using the API are added to the repository (#13285) (#13302)

Partial Backport #13285

Fix #12426

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: Lauris BH <lauris@nix.lv>

models/topic.go

@@ -197,10 +197,13 @@ func FindTopics(opts *FindTopicOptions) (topics []*Topic, err error) {
 
 // GetRepoTopicByName retrives topic from name for a repo if it exist
 func GetRepoTopicByName(repoID int64, topicName string) (*Topic, error) {
+	return getRepoTopicByName(x, repoID, topicName)
+}
+func getRepoTopicByName(e Engine, repoID int64, topicName string) (*Topic, error) {
 	var cond = builder.NewCond()
 	var topic Topic
 	cond = cond.And(builder.Eq{"repo_topic.repo_id": repoID}).And(builder.Eq{"topic.name": topicName})
-	sess := x.Table("topic").Where(cond)
+	sess := e.Table("topic").Where(cond)
 	sess.Join("INNER", "repo_topic", "repo_topic.topic_id = topic.id")
 	has, err := sess.Get(&topic)
 	if has {
@@ -211,7 +214,13 @@ func GetRepoTopicByName(repoID int64, topicName string) (*Topic, error) {
 
 // AddTopic adds a topic name to a repository (if it does not already have it)
 func AddTopic(repoID int64, topicName string) (*Topic, error) {
-	topic, err := GetRepoTopicByName(repoID, topicName)
+	sess := x.NewSession()
+	defer sess.Close()
+	if err := sess.Begin(); err != nil {
+		return nil, err
+	}
+
+	topic, err := getRepoTopicByName(sess, repoID, topicName)
 	if err != nil {
 		return nil, err
 	}
@@ -220,7 +229,25 @@ func AddTopic(repoID int64, topicName string) (*Topic, error) {
 		return topic, nil
 	}
 
-	return addTopicByNameToRepo(x, repoID, topicName)
+	topic, err = addTopicByNameToRepo(sess, repoID, topicName)
+	if err != nil {
+		return nil, err
+	}
+
+	topicNames := make([]string, 0, 25)
+	if err := sess.Select("name").Table("topic").
+		Join("INNER", "repo_topic", "repo_topic.topic_id = topic.id").
+		Where("repo_topic.repo_id = ?", repoID).Desc("topic.repo_count").Find(&topicNames); err != nil {
+		return nil, err
+	}
+
+	if _, err := sess.ID(repoID).Cols("topics").Update(&Repository{
+		Topics: topicNames,
+	}); err != nil {
+		return nil, err
+	}
+
+	return topic, sess.Commit()
 }
 
 // DeleteTopic removes a topic name from a repository (if it has it)