message_edit: Close message edit UI after message is moved.

Currently, if we navigate to some other topic/stream
while the message is being moved, the message edit UI
still remains open as we do not get its `row` in
`message_lists.current` since the message has not moved yet
to the stream/topic we navigated.

Hence the correct thing to do would be to delete
the message_id from `currently_editing_messages` if it
exists there but we cannot find the row.

Fixes #21724.

frontend_tests/node_tests/message_events.js

@@ -88,10 +88,6 @@ run_test("update_messages", () => {
         },
     ];
 
-    message_lists.current.get_row = (message_id) => {
-        assert.equal(message_id, 111);
-        return ["row-stub"];
-    };
     message_lists.current.view = {};
 
     let rendered_mgs;
@@ -103,7 +99,7 @@ run_test("update_messages", () => {
 
     const side_effects = [
         [condense, "un_cache_message_content_height"],
-        [message_edit, "end_message_row_edit"],
+        [message_edit, "end_message_edit"],
         [notifications, "received_messages"],
         [unread_ui, "update_unread_counts"],
         [stream_list, "update_streams_sidebar"],

static/js/message_edit.js

@@ -805,6 +805,17 @@ export function end_message_row_edit($row) {
     $row.find("input.message_edit_topic").trigger("blur");
 }
 
+export function end_message_edit(message_id) {
+    const $row = message_lists.current.get_row(message_id);
+    if ($row.length > 0) {
+        end_message_row_edit($row);
+    } else if (currently_editing_messages.has(message_id)) {
+        // We should delete the message_id from currently_editing_messages
+        // if it exists there but we cannot find the row.
+        currently_editing_messages.delete(message_id);
+    }
+}
+
 export function save_inline_topic_edit($row) {
     const msg_list = message_lists.current;
     let message_id = rows.id_for_recipient_row($row);

static/js/message_events.js

@@ -175,10 +175,8 @@ export function update_messages(events) {
             msg.is_me_message = event.is_me_message;
         }
 
-        const $row = message_lists.current.get_row(event.message_id);
-        if ($row.length > 0) {
-            message_edit.end_message_row_edit($row);
-        }
+        // mark the current message edit attempt as complete.
+        message_edit.end_message_edit(event.message_id);
 
         const new_topic = util.get_edit_event_topic(event);