Added topics validation, fixed repo topics duplication (#4031)

Signed-off-by: Alexey Terentyev <axifnx@gmail.com>

models/topic.go

@@ -11,6 +11,7 @@ import (
 	"code.gitea.io/gitea/modules/util"
 
 	"github.com/go-xorm/builder"
+	"regexp"
 )
 
 func init() {
@@ -20,6 +21,8 @@ func init() {
 	)
 }
 
+var topicPattern = regexp.MustCompile(`^[a-z0-9+#_.-]+$`)
+
 // Topic represents a topic of repositories
 type Topic struct {
 	ID          int64
@@ -51,6 +54,26 @@ func (err ErrTopicNotExist) Error() string {
 	return fmt.Sprintf("topic is not exist [name: %s]", err.Name)
 }
 
+func TopicValidator(topic string) bool {
+	return len(topic) <= 35 && topicPattern.MatchString(topic)
+}
+
+// Remove duplicates from topics slice
+func RemoveDuplicateTopics(topics []string) []string {
+	// Map to record duplicates
+	saved := make(map[string]struct{}, len(topics))
+	i := 0
+	for _, v := range topics {
+		v = strings.TrimSpace(strings.ToLower(v))
+		if _, ok := saved[v]; !ok {
+			saved[v] = struct{}{}
+			topics[i] = v
+			i++
+		}
+	}
+	return topics[:i]
+}
+
 // GetTopicByName retrieves topic by name
 func GetTopicByName(name string) (*Topic, error) {
 	var topic Topic

options/locale/locale_en-US.ini

@@ -1167,6 +1167,8 @@ branch.protected_deletion_failed = Branch '%s' is protected. It cannot be delete
 
 topic.manage_topics = Manage Topics
 topic.done = Done
+topic.count_prompt = You can't select more than 25 topics
+topic.format_prompt = Topics must use letter or number and can include hyphen(-), underscore(_), plus(+), hash(#), dot(.) with max length of 35
 
 [org]
 org_name_holder = Organization Name

routers/repo/topic.go

@@ -13,7 +13,7 @@ import (
 )
 
 // TopicPost response for creating repository
-func TopicPost(ctx *context.Context) {
+func TopicsPost(ctx *context.Context) {
 	if ctx.User == nil {
 		ctx.JSON(403, map[string]interface{}{
 			"message": "Only owners could change the topics.",
@@ -27,6 +27,33 @@ func TopicPost(ctx *context.Context) {
 		topics = strings.Split(topicsStr, ",")
 	}
 
+	topics = models.RemoveDuplicateTopics(topics)
+
+	if len(topics) > 25 {
+		log.Error(2, "Incorrect number of topics(max 25): %v", )
+		ctx.JSON(422, map[string]interface{}{
+			"invalidTopics": topics[:0],
+			"message": ctx.Tr("repo.topic.count_error"),
+		})
+		return
+	}
+
+	var invalidTopics = make([]string, 0)
+	for _, topic := range topics {
+		if !models.TopicValidator(topic) {
+			invalidTopics = append(invalidTopics, topic)
+		}
+	}
+
+	if len(invalidTopics) > 0 {
+		log.Error(2, "Invalid topics: %v", invalidTopics)
+		ctx.JSON(422, map[string]interface{}{
+			"invalidTopics": invalidTopics,
+			"message": ctx.Tr("repo.topic.pattern_error"),
+		})
+		return
+	}
+
 	err := models.SaveTopics(ctx.Repo.Repository.ID, topics...)
 	if err != nil {
 		log.Error(2, "SaveTopics failed: %v", err)

routers/routes/routes.go

@@ -626,7 +626,7 @@ func RegisterRoutes(m *macaron.Macaron) {
 	}, context.RepoAssignment(), context.UnitTypes(), context.LoadRepoUnits(), context.CheckUnit(models.UnitTypeReleases))
 
 	m.Group("/:username/:reponame", func() {
-		m.Post("/topics", repo.TopicPost)
+		m.Post("/topics", repo.TopicsPost)
 	}, context.RepoAssignment(), reqRepoAdmin)
 
 	m.Group("/:username/:reponame", func() {