edit_history: Add supoort for empty topic name.

zerver/lib/topic.py

@@ -327,3 +327,11 @@ def maybe_rename_general_chat_to_empty_topic(topic_name: str) -> str:
     if topic_name == "general chat":
         topic_name = ""
     return topic_name
+
+
+def maybe_rename_empty_topic_to_general_chat(
+    topic_name: str, is_channel_message: bool, allow_empty_topic_name: bool
+) -> str:
+    if is_channel_message and topic_name == "" and not allow_empty_topic_name:
+        return "general chat"
+    return topic_name

zerver/tornado/event_queue.py

@@ -1630,6 +1630,19 @@ def process_stream_typing_notification_event(event: Mapping[str, Any], users: It
             client.add_event(event)
 
 
+def process_mark_message_unread_event(event: Mapping[str, Any], users: Iterable[int]) -> None:
+    for user_profile_id in users:
+        for client in get_client_descriptors_for_user(user_profile_id):
+            if not client.accepts_event(event):
+                continue
+
+            for message_id, message_detail in event["message_details"].items():
+                if message_detail["type"] == "stream" and message_detail.get("topic") == "" and not client.empty_topic_name:
+                    event["message_details"][message_id]["topic"] = "general chat"
+
+            client.add_event(event)
+
+
 def process_notification(notice: Mapping[str, Any]) -> None:
     event: Mapping[str, Any] = notice["event"]
     users: list[int] | list[Mapping[str, Any]] = notice["users"]
@@ -1662,6 +1675,8 @@ def process_notification(notice: Mapping[str, Any]) -> None:
         process_user_topic_event(event, cast(list[int], users))
     elif event["type"] == "typing" and event["message_type"] == "stream":
         process_stream_typing_notification_event(event, cast(list[int], users))
+    elif event["type"] == "update_message_flags" and event["op"] == "remove" and event["flag"] == "read":
+        process_mark_message_unread_event(event, cast(list[int], users))
     elif event["type"] == "cleanup_queue":
         # cleanup_event_queue may generate this event to forward cleanup
         # requests to the right shard.

zerver/views/message_edit.py

@@ -23,13 +23,16 @@ from zerver.lib.message import (
 from zerver.lib.request import RequestNotes
 from zerver.lib.response import json_success
 from zerver.lib.timestamp import datetime_to_timestamp
+from zerver.lib.topic import maybe_rename_empty_topic_to_general_chat
 from zerver.lib.typed_endpoint import OptionalTopic, PathOnly, typed_endpoint
 from zerver.lib.types import EditHistoryEvent, FormattedEditHistoryEvent
 from zerver.models import Message, UserProfile
 
 
 def fill_edit_history_entries(
-    raw_edit_history: list[EditHistoryEvent], message: Message
+    raw_edit_history: list[EditHistoryEvent],
+    message: Message,
+    allow_empty_topic_name: bool,
 ) -> list[FormattedEditHistoryEvent]:
     """
     This fills out the message edit history entries from the database
@@ -39,7 +42,10 @@ def fill_edit_history_entries(
     """
     prev_content = message.content
     prev_rendered_content = message.rendered_content
-    prev_topic_name = message.topic_name()
+    is_channel_message = message.is_stream_message()
+    prev_topic_name = maybe_rename_empty_topic_to_general_chat(
+        message.topic_name(), is_channel_message, allow_empty_topic_name
+    )
 
     # Make sure that the latest entry in the history corresponds to the
     # message's last edit time
@@ -58,7 +64,9 @@ def fill_edit_history_entries(
         }
 
         if "prev_topic" in edit_history_event:
-            prev_topic_name = edit_history_event["prev_topic"]
+            prev_topic_name = maybe_rename_empty_topic_to_general_chat(
+                edit_history_event["prev_topic"], is_channel_message, allow_empty_topic_name
+            )
             formatted_entry["prev_topic"] = prev_topic_name
 
         # Fill current values for content/rendered_content.
@@ -99,6 +107,7 @@ def get_message_edit_history(
     user_profile: UserProfile,
     *,
     message_id: PathOnly[NonNegativeInt],
+    allow_empty_topic_name: Json[bool] = False,
 ) -> HttpResponse:
     if not user_profile.realm.allow_edit_history:
         raise JsonableError(_("Message edit history is disabled in this organization"))
@@ -111,7 +120,9 @@ def get_message_edit_history(
         raw_edit_history = []
 
     # Fill in all the extra data that will make it usable
-    message_edit_history = fill_edit_history_entries(raw_edit_history, message)
+    message_edit_history = fill_edit_history_entries(
+        raw_edit_history, message, allow_empty_topic_name
+    )
     return json_success(request, data={"message_history": list(reversed(message_edit_history))})