From 8828e96b87b21604d11902d2563927029d620cea Mon Sep 17 00:00:00 2001
From: Tim Abbott <tabbott@zulipchat.com>
Date: Wed, 11 Oct 2017 20:31:32 -0700
Subject: [PATCH] presence: Avoid checking activity when reloading.

We sometimes get blueslip errors from browsers that are clearly still
attempting to reload long after they should have.  These browsers can
produce a lot of unnecessary presence update exceptions.

To solve that, we start checking reload_in_progress in the presence
code path.

While we're at it, we also add some blueslip logging for the reload
code path, in case it becomes useful when debugging future issues.
---
 frontend_tests/node_tests/activity.js | 14 ++++++++++++++
 static/js/activity.js                 |  5 ++++-
 static/js/reload.js                   |  6 +++++-
 static/js/server_events.js            |  1 +
 4 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/frontend_tests/node_tests/activity.js b/frontend_tests/node_tests/activity.js
index cc450ff7e8..64b69b88b6 100644
--- a/frontend_tests/node_tests/activity.js
+++ b/frontend_tests/node_tests/activity.js
@@ -39,6 +39,13 @@ zrequire('presence');
 zrequire('people');
 zrequire('activity');
 
+set_global('blueslip', {
+    log: function () {},
+});
+
+set_global('reload', {
+    is_in_progress: function () {return false;},
+});
 set_global('resize', {
     resize_page_components: function () {},
 });
@@ -706,4 +713,11 @@ $('.user-list-filter').is = function (sel) {
   assert($('#zephyr-mirror-error').hasClass('show'));
   assert(!activity.new_user_input);
   assert(!activity.has_focus);
+
+  // Now execute the reload-in-progress code path
+  reload.is_in_progress = function () {
+      return true;
+  };
+  activity.initialize();
+
 }());
diff --git a/static/js/activity.js b/static/js/activity.js
index 82a9aba656..bdee60177f 100644
--- a/static/js/activity.js
+++ b/static/js/activity.js
@@ -399,8 +399,11 @@ exports.update_huddles = function () {
     exports.update_scrollbar.group_pms();
 };
 
-
 function focus_ping(want_redraw) {
+    if (reload.is_in_progress()) {
+        blueslip.log("Skipping querying presence because reload in progress");
+        return;
+    }
     channel.post({
         url: '/json/users/me/presence',
         data: {status: (exports.has_focus) ? exports.ACTIVE : exports.IDLE,
diff --git a/static/js/reload.js b/static/js/reload.js
index a32e981dc0..9d194293a0 100644
--- a/static/js/reload.js
+++ b/static/js/reload.js
@@ -175,7 +175,10 @@ exports.initialize = function reload__initialize() {
 };
 
 function do_reload_app(send_after_reload, save_pointer, save_narrow, save_compose, message) {
-    if (reload_in_progress) { return; }
+    if (reload_in_progress) {
+        blueslip.log("do_reload_app: Doing nothing since reload_in_progress");
+        return;
+    }
 
     // TODO: we should completely disable the UI here
     if (save_pointer || save_narrow || save_compose) {
@@ -305,6 +308,7 @@ window.addEventListener('beforeunload', function () {
     // When that happens we reload the page to correct the problem. If this
     // happens before the navigation is complete the user is kept captive at
     // zulip.
+    blueslip.log("Setting reload_in_progress in beforeunload handler");
     reload_in_progress = true;
 });
 
diff --git a/static/js/server_events.js b/static/js/server_events.js
index 358d4adb76..2d0be4b07e 100644
--- a/static/js/server_events.js
+++ b/static/js/server_events.js
@@ -270,6 +270,7 @@ exports.cleanup_event_queue = function cleanup_event_queue() {
     if (page_params.event_queue_expired === true) {
         return;
     }
+    blueslip.log("Cleaning up our event queue");
     // Set expired because in a reload we may be called twice.
     page_params.event_queue_expired = true;
     channel.del({