unreads: Use case i9e lookups, preserving case.

This commit makes the topics having different
casings for the same topic be stored under
the same QueueList by making the lookups
lowercase while preserving one of the
variants of the used topic case.

Fixes zulip#980.

Author: apoorvapendse

lib/model/unreads.dart

@@ -41,13 +41,15 @@ class Unreads extends ChangeNotifier {
     required ChannelStore channelStore,
   }) {
     final streams = <int, Map<String, QueueList<int>>>{};
+    final topicMapper = <String, String>{};
     final dms = <DmNarrow, QueueList<int>>{};
     final mentions = Set.of(initial.mentions);
 
     for (final unreadChannelSnapshot in initial.channels) {
       final streamId = unreadChannelSnapshot.streamId;
       final topic = unreadChannelSnapshot.topic;
-      (streams[streamId] ??= {})[topic] = QueueList.from(unreadChannelSnapshot.unreadMessageIds);
+      topicMapper[topic.toLowerCase()] = topic;
+      (streams[streamId] ??= {})[topic.toLowerCase()] = QueueList.from(unreadChannelSnapshot.unreadMessageIds);
     }
 
     for (final unreadDmSnapshot in initial.dms) {
@@ -64,6 +66,7 @@ class Unreads extends ChangeNotifier {
     return Unreads._(
       channelStore: channelStore,
       streams: streams,
+      topicMapper: topicMapper,
       dms: dms,
       mentions: mentions,
       oldUnreadsMissing: initial.oldUnreadsMissing,
@@ -74,6 +77,7 @@ class Unreads extends ChangeNotifier {
   Unreads._({
     required this.channelStore,
     required this.streams,
+    required this.topicMapper,
     required this.dms,
     required this.mentions,
     required this.oldUnreadsMissing,
@@ -88,6 +92,9 @@ class Unreads extends ChangeNotifier {
   /// Unread stream messages, as: stream ID → topic → message IDs (sorted).
   final Map<int, Map<String, QueueList<int>>> streams;
 
+  // Maps lowercase topic names for lookup to one of the variants of the topic (case preserving).
+  final Map<String, String> topicMapper;
+
   /// Unread DM messages, as: DM narrow → message IDs (sorted).
   final Map<DmNarrow, QueueList<int>> dms;
 
@@ -368,7 +375,7 @@ class Unreads extends ChangeNotifier {
               switch (detail.type) {
                 case MessageType.stream:
                   final topics = (newlyUnreadInStreams[detail.streamId!] ??= {});
-                  final messageIds = (topics[detail.topic!] ??= QueueList());
+                  final messageIds = (topics[detail.topic!.toLowerCase()] ??= QueueList());
                   messageIds.add(messageId);
                 case MessageType.direct:
                   final narrow = DmNarrow.ofUpdateMessageFlagsMessageDetail(selfUserId: selfUserId,
@@ -437,7 +444,8 @@ class Unreads extends ChangeNotifier {
   }
 
   void _addLastInStreamTopic(int messageId, int streamId, String topic) {
-    ((streams[streamId] ??= {})[topic] ??= QueueList()).addLast(messageId);
+    topicMapper[topic.toLowerCase()] = topic;
+    ((streams[streamId] ??= {})[topic.toLowerCase()] ??= QueueList()).addLast(messageId);
   }
 
   // [messageIds] must be sorted ascending and without duplicates.

lib/widgets/inbox.dart

@@ -136,11 +136,11 @@ class _InboxPageState extends State<InboxPageBody> with PerAccountStoreAwareStat
       int countInStream = 0;
       bool streamHasMention = false;
       for (final MapEntry(key: topic, value: messageIds) in topics.entries) {
-        if (!store.isTopicVisible(streamId, topic)) continue;
+        if (!store.isTopicVisible(streamId, unreadsModel != null? unreadsModel!.topicMapper[topic]! : topic)) continue;
         final countInTopic = messageIds.length;
         final hasMention = messageIds.any((messageId) => unreadsModel!.mentions.contains(messageId));
         if (hasMention) streamHasMention = true;
-        topicItems.add((topic, countInTopic, hasMention, messageIds.last));
+        topicItems.add((unreadsModel!.topicMapper[topic]!, countInTopic, hasMention, messageIds.last));
         countInStream += countInTopic;
       }
       if (countInStream == 0) {

test/model/unreads_test.dart

@@ -68,7 +68,7 @@ void main() {
       switch (message) {
         case StreamMessage():
           final perTopic = expectedStreams[message.streamId] ??= {};
-          final messageIds = perTopic[message.topic] ??= QueueList();
+          final messageIds = perTopic[message.topic.toLowerCase()] ??= QueueList();
           messageIds.add(message.id);
         case DmMessage():
           final narrow = DmNarrow.ofMessage(message, selfUserId: eg.selfUser.userId);
@@ -289,6 +289,7 @@ void main() {
         final stream2 = eg.stream(streamId: 2);
         for (final (oldStream, newStream, oldTopic, newTopic) in [
           (stream1, stream1, 'a', 'a'),
+          (stream1, stream1, 'a', 'A'),
           (stream1, stream1, 'a', 'b'),
           (stream1, stream2, 'a', 'a'),
           (stream1, stream2, 'a', 'b'),