From bf14f4cd7b2ddc2bd01ac5b64a7250745d11c2d3 Mon Sep 17 00:00:00 2001
From: Mohit Gupta <mohitgupta3mail@gmail.com>
Date: Tue, 12 Feb 2019 07:55:26 +0530
Subject: [PATCH] notification: Show wrong narrow notification for non locally
 echoed message.

Show "sent to different narrow" notification and other such notification by
notifications.notify_local_mixes for non locally echoed message sent by
current client.

With significant new comments added by tabbott.

Fixes: #11488.
---
 frontend_tests/node_tests/server_events.js |  1 +
 static/js/message_events.js                |  3 +++
 static/js/notifications.js                 |  9 ++++++++-
 static/js/server_events.js                 | 18 +++++++++++++++++-
 4 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/frontend_tests/node_tests/server_events.js b/frontend_tests/node_tests/server_events.js
index 225aae2a73..f635ae994e 100644
--- a/frontend_tests/node_tests/server_events.js
+++ b/frontend_tests/node_tests/server_events.js
@@ -9,6 +9,7 @@ global.stub_out_jquery();
 zrequire('message_store');
 zrequire('server_events_dispatch');
 zrequire('server_events');
+zrequire('sent_messages');
 
 set_global('blueslip', global.make_zblueslip());
 set_global('channel', {});
diff --git a/static/js/message_events.js b/static/js/message_events.js
index 4f0c69089f..e12f697410 100644
--- a/static/js/message_events.js
+++ b/static/js/message_events.js
@@ -85,6 +85,9 @@ exports.insert_new_messages = function insert_new_messages(messages, sent_by_thi
 
     if (sent_by_this_client) {
         var need_user_to_scroll = render_info && render_info.need_user_to_scroll;
+        // sent_by_this_client will be true if ANY of the messages
+        // were sent by this client; notifications.notify_local_mixes
+        // will filter out any not sent by us.
         notifications.notify_local_mixes(messages, need_user_to_scroll);
     }
 
diff --git a/static/js/notifications.js b/static/js/notifications.js
index 785bb5108e..6df04e19af 100644
--- a/static/js/notifications.js
+++ b/static/js/notifications.js
@@ -598,11 +598,18 @@ exports.notify_local_mixes = function (messages, need_user_to_scroll) {
         checkable locally, so we may want to execute this code
         earlier in the codepath at some point and possibly punt
         on local rendering.
+
+        Possible cleanup: Arguably, we should call this function
+        unconditionally and just check if message.local_id is in
+        sent_messages.messages here.
     */
 
     _.each(messages, function (message) {
         if (!people.is_my_user_id(message.sender_id)) {
-            blueslip.warn('We did not expect messages sent by others to get here');
+            // This can happen if the client is offline for a while
+            // around the time this client sends a message; see the
+            // caller of message_events.insert_new_messages.
+            blueslip.info('Slightly unexpected: A message not sent by us batches with those that were.');
             return;
         }
 
diff --git a/static/js/server_events.js b/static/js/server_events.js
index d8ade3d8c4..a97ef32254 100644
--- a/static/js/server_events.js
+++ b/static/js/server_events.js
@@ -104,7 +104,23 @@ function get_events_success(events) {
         try {
             messages = echo.process_from_server(messages);
             _.each(messages, message_store.set_message_booleans);
-            message_events.insert_new_messages(messages);
+            var sent_by_this_client = false;
+            _.each(messages, function (msg) {
+                var msg_state = sent_messages.messages[msg.local_id];
+                if (msg_state) {
+                    // Almost every time, this message will be the
+                    // only one in messages, because multiple messages
+                    // being returned by get_events usually only
+                    // happens when a client is offline, but we know
+                    // this client just sent a message in this batch
+                    // of events.  But in any case,
+                    // insert_new_messages handles multiple messages,
+                    // only one of which was sent by this client,
+                    // correctly.
+                    sent_by_this_client = true;
+                }
+            });
+            message_events.insert_new_messages(messages, sent_by_this_client);
         } catch (ex2) {
             blueslip.error('Failed to insert new messages\n' +
                            blueslip.exception_msg(ex2),