room names: fix a bug which produced incorrect names due to display name changes

Add regression tests for this.

internal/event.go

@@ -0,0 +1,19 @@
+package internal
+
+import "github.com/tidwall/gjson"
+
+func IsMembershipChange(eventJSON gjson.Result) bool {
+	// membership event possibly, make sure the membership has changed else
+	// things like display name changes will count as membership events :(
+	prevMembership := "leave"
+	pm := eventJSON.Get("unsigned.prev_content.membership")
+	if pm.Exists() && pm.Str != "" {
+		prevMembership = pm.Str
+	}
+	currMembership := "leave"
+	cm := eventJSON.Get("content.membership")
+	if cm.Exists() && cm.Str != "" {
+		currMembership = cm.Str
+	}
+	return prevMembership != currMembership // membership was changed
+}

room_names_test.go

@@ -42,7 +42,23 @@ func TestRoomNames(t *testing.T) {
 		{
 			roomID: "!TestRoomNames_empty:localhost",
 			name:   "Empty Room",
-			events: createRoomState(t, alice, latestTimestamp),
+			events: createRoomState(t, alice, latestTimestamp.Add(time.Second)),
+		},
+		{
+			roomID: "!TestRoomNames_dm_name_set_after_join:localhost",
+			name:   "Bob",
+			state: append(createRoomState(t, alice, latestTimestamp), []json.RawMessage{
+				testutils.NewStateEvent(t, "m.room.member", bob, bob, map[string]interface{}{"membership": "join"}, testutils.WithTimestamp(latestTimestamp)),
+			}...),
+			events: []json.RawMessage{
+				testutils.NewStateEvent(
+					t, "m.room.member", bob, bob, map[string]interface{}{"membership": "join", "displayname": "Bob"}, testutils.WithTimestamp(latestTimestamp),
+					testutils.WithUnsigned(map[string]interface{}{
+						"prev_content": map[string]interface{}{
+							"membership": "join",
+						},
+					})),
+			},
 		},
 	}
 	v2.addAccount(alice, aliceToken)
@@ -53,6 +69,7 @@ func TestRoomNames(t *testing.T) {
 	})
 
 	checkRoomNames := func(sessionID string) {
+		t.Helper()
 		// do a sync, make sure room names are sensible
 		res := v3.mustDoV3Request(t, aliceToken, sync3.Request{
 			Rooms: sync3.SliceRanges{

state/event_table.go

@@ -6,6 +6,7 @@ import (
 	"math"
 
 	"github.com/jmoiron/sqlx"
+	"github.com/matrix-org/sync-v3/internal"
 	"github.com/matrix-org/sync-v3/sqlutil"
 	"github.com/tidwall/gjson"
 )
@@ -124,7 +125,7 @@ func (t *EventTable) Insert(txn *sqlx.Tx, events []Event) (int, error) {
 				return 0, fmt.Errorf("membership event missing membership key")
 			}
 			// genuine changes mark the membership event
-			if isMembershipChange(evJSON) {
+			if internal.IsMembershipChange(evJSON) {
 				ev.Membership = membershipResult.Str
 			} else {
 				// profile changes have _ prefix.
@@ -333,19 +334,3 @@ func (c EventChunker) Len() int {
 func (c EventChunker) Subslice(i, j int) sqlutil.Chunker {
 	return c[i:j]
 }
-
-func isMembershipChange(eventJSON gjson.Result) bool {
-	// membership event possibly, make sure the membership has changed else
-	// things like display name changes will count as membership events :(
-	prevMembership := "leave"
-	pm := eventJSON.Get("unsigned.prev_content.membership")
-	if pm.Exists() && pm.Str != "" {
-		prevMembership = pm.Str
-	}
-	currMembership := "leave"
-	cm := eventJSON.Get("content.membership")
-	if cm.Exists() && cm.Str != "" {
-		currMembership = cm.Str
-	}
-	return prevMembership != currMembership // membership was changed
-}

state/storage.go

@@ -133,8 +133,12 @@ func (s *Storage) MetadataForAllRooms() (map[string]internal.RoomMetadata, error
 		SELECT room_id, event, rank() OVER (
 			PARTITION BY room_id ORDER BY event_nid DESC
 		) FROM syncv3_events WHERE (
-			membership='join' OR membership='invite' OR (membership='_join' AND before_state_snapshot_id=0)
-		) AND event_type='m.room.member'
+			membership='join' OR membership='invite' OR membership='_join'
+		) AND event_type='m.room.member' AND event_nid IN (
+			SELECT unnest(events) FROM syncv3_snapshots WHERE syncv3_snapshots.snapshot_id IN (
+				SELECT current_snapshot_id FROM syncv3_rooms
+			)
+		)
 	) rf WHERE rank <= 6`)
 	if err != nil {
 		return nil, fmt.Errorf("failed to query heroes: %s", err)

sync3/globalcache.go

@@ -166,23 +166,38 @@ func (c *GlobalCache) OnNewEvent(
 	case "m.room.member":
 		if ed.stateKey != nil {
 			membership := ed.content.Get("membership").Str
-			if membership == "invite" {
-				metadata.InviteCount += 1
-			} else if membership == "join" {
-				metadata.JoinCount += 1
-			} else if membership == "leave" || membership == "ban" {
-				metadata.JoinCount -= 1
-				// remove this user as a hero
-				metadata.RemoveHero(*ed.stateKey)
-			}
-			if gjson.ParseBytes(ed.event).Get("unsigned.prev_content.membership").Str == "invite" {
-				metadata.InviteCount -= 1
+			eventJSON := gjson.ParseBytes(ed.event)
+			if internal.IsMembershipChange(eventJSON) {
+				if membership == "invite" {
+					metadata.InviteCount += 1
+				} else if membership == "join" {
+					metadata.JoinCount += 1
+				} else if membership == "leave" || membership == "ban" {
+					metadata.JoinCount -= 1
+					// remove this user as a hero
+					metadata.RemoveHero(*ed.stateKey)
+				}
+
+				if eventJSON.Get("unsigned.prev_content.membership").Str == "invite" {
+					metadata.InviteCount -= 1
+				}
 			}
 			if len(metadata.Heroes) < 6 && (membership == "join" || membership == "invite") {
-				metadata.Heroes = append(metadata.Heroes, internal.Hero{
-					ID:   *ed.stateKey,
-					Name: ed.content.Get("displayname").Str,
-				})
+				// try to find the existing hero e.g they changed their display name
+				found := false
+				for i := range metadata.Heroes {
+					if metadata.Heroes[i].ID == *ed.stateKey {
+						metadata.Heroes[i].Name = ed.content.Get("displayname").Str
+						found = true
+						break
+					}
+				}
+				if !found {
+					metadata.Heroes = append(metadata.Heroes, internal.Hero{
+						ID:   *ed.stateKey,
+						Name: ed.content.Get("displayname").Str,
+					})
+				}
 			}
 		}
 	}

v3_test.go

@@ -323,6 +323,7 @@ func MatchRoomNotificationCount(count int64) roomMatcher {
 type roomEvents struct {
 	roomID string
 	name   string
+	state  []json.RawMessage
 	events []json.RawMessage
 }
 
@@ -345,6 +346,11 @@ func v2JoinTimeline(joinEvents ...roomEvents) map[string]sync2.SyncV2JoinRespons
 		data.Timeline = sync2.TimelineResponse{
 			Events: re.events,
 		}
+		if re.state != nil {
+			data.State = sync2.EventsResponse{
+				Events: re.state,
+			}
+		}
 		result[re.roomID] = data
 	}
 	return result