update user object only when topics available

endpoints/openrtb2/auction.go

@@ -2035,10 +2035,6 @@ func setAuctionTypeImplicitly(r *openrtb_ext.RequestWrapper) {
 
 // (100);v=chrome.1:1:20, (200);v=chrome.1:1:40, (300);v=chrome.1:1:60, ();p=P
 func setSecBrowsingTopcisImplicitly(httpReq *http.Request, r *openrtb_ext.RequestWrapper, cfg *config.Configuration) {
-	if r.User == nil {
-		r.User = &openrtb2.User{}
-	}
-
 	topicsDomain := "TOPICS_DOMAIN"
 	if cfg != nil {
 		topicsDomain = cfg.Auction.PrivacySandbox.TopicsDomain
@@ -2052,9 +2048,9 @@ func setSecBrowsingTopcisImplicitly(httpReq *http.Request, r *openrtb_ext.Reques
 	// segtax-segclass-name-segIds
 	userData := map[int]map[string]map[string]map[string]struct{}{}
 	secBrowsingTopicsArr := strings.Split(secBrowsingTopics, ",")
-	c := 0
+	selectedFields := 0
 	for _, seg := range secBrowsingTopicsArr {
-		if c >= 10 {
+		if selectedFields >= 10 {
 			break
 		}
 
@@ -2115,7 +2111,15 @@ func setSecBrowsingTopcisImplicitly(httpReq *http.Request, r *openrtb_ext.Reques
 			}
 		}
 
-		c++
+		selectedFields++
+	}
+
+	if selectedFields == 0 {
+		return
+	}
+
+	if r.User == nil {
+		r.User = &openrtb2.User{}
 	}
 
 	type extData struct {

endpoints/openrtb2/auction_test.go

@@ -6203,7 +6203,7 @@ func Test_setSecBrowsingTopcisImplicitly(t *testing.T) {
 				r:       &openrtb_ext.RequestWrapper{BidRequest: &openrtb2.BidRequest{}},
 				cfg:     &config.Configuration{Auction: config.Auction{PrivacySandbox: config.PrivacySandbox{TopicsDomain: "TOPICS_DOMAIN"}}},
 			},
-			wantUser: &openrtb2.User{},
+			wantUser: nil,
 		},
 		{
 			name: "Sec-Browsing-Topics with empty value, request.user.data empty, no change in user data",
@@ -6216,7 +6216,7 @@ func Test_setSecBrowsingTopcisImplicitly(t *testing.T) {
 				r:   &openrtb_ext.RequestWrapper{BidRequest: &openrtb2.BidRequest{}},
 				cfg: &config.Configuration{Auction: config.Auction{PrivacySandbox: config.PrivacySandbox{TopicsDomain: "TOPICS_DOMAIN"}}},
 			},
-			wantUser: &openrtb2.User{},
+			wantUser: nil,
 		},
 		{
 			name: "Sec-Browsing-Topics with invalid value, request.user.data empty, no change in user data",
@@ -6229,7 +6229,7 @@ func Test_setSecBrowsingTopcisImplicitly(t *testing.T) {
 				r:   &openrtb_ext.RequestWrapper{BidRequest: &openrtb2.BidRequest{}},
 				cfg: &config.Configuration{Auction: config.Auction{PrivacySandbox: config.PrivacySandbox{TopicsDomain: "TOPICS_DOMAIN"}}},
 			},
-			wantUser: &openrtb2.User{},
+			wantUser: nil,
 		},
 		{
 			name: "Sec-Browsing-Topics with finish padding, request.user.data empty, no change in user data",
@@ -6242,7 +6242,7 @@ func Test_setSecBrowsingTopcisImplicitly(t *testing.T) {
 				r:   &openrtb_ext.RequestWrapper{BidRequest: &openrtb2.BidRequest{}},
 				cfg: &config.Configuration{Auction: config.Auction{PrivacySandbox: config.PrivacySandbox{TopicsDomain: "TOPICS_DOMAIN"}}},
 			},
-			wantUser: &openrtb2.User{},
+			wantUser: nil,
 		},
 		{
 			name: "Sec-Browsing-Topics with one valid field, request.user.data empty, valid field data added to req.user.data",
@@ -6897,7 +6897,7 @@ func Test_setSecBrowsingTopcisImplicitly(t *testing.T) {
 			setSecBrowsingTopcisImplicitly(tt.args.httpReq, tt.args.r, tt.args.cfg)
 
 			// sequence is not garunteed in request.user.data as we're using a map
-			if tt.wantUser.Data != nil {
+			if tt.wantUser != nil && tt.wantUser.Data != nil {
 				sort.Slice(tt.wantUser.Data, func(i, j int) bool {
 					return string(tt.wantUser.Data[i].Ext) < string(tt.wantUser.Data[j].Ext)
 				})
@@ -6908,7 +6908,7 @@ func Test_setSecBrowsingTopcisImplicitly(t *testing.T) {
 					})
 				}
 			}
-			if tt.args.r.User.Data != nil {
+			if tt.args.r.User != nil && tt.args.r.User.Data != nil {
 				sort.Slice(tt.args.r.User.Data, func(i, j int) bool {
 					return string(tt.args.r.User.Data[i].Ext) < string(tt.args.r.User.Data[j].Ext)
 				})