subscription: Fix unexpected blueslip warnings on add subscriber.

In stream settings, if user add subscriber to unsubscribed public
stream from `Add` input widget it gives lots of blueslip warnings,
cause user isn't subscribed to public stream.

Fix this by changing condition to `sub.can_access_subscriber` from
`sub.subscribed` in blueslip warning, cause user can access
subscribers in such cases even if not subscribed to stream.

Tweaked by tabbott to make the node tests pass.

frontend_tests/node_tests/compose_fade.js

@@ -1,5 +1,7 @@
 set_global('$', function () {
 });
+set_global('blueslip', {});
+global.blueslip.warn = function () {};
 
 zrequire('util');
 zrequire('stream_data');
@@ -36,6 +38,7 @@ people.add(bob);
         stream_id: 101,
         name: 'social',
         subscribed: true,
+        can_access_subscribers: true,
     };
     stream_data.add_sub('social', sub);
     stream_data.set_subscribers(sub, [me.user_id, alice.user_id]);

frontend_tests/node_tests/stream_data.js

@@ -168,6 +168,7 @@ zrequire('marked', 'third/marked/lib/marked');
     people.add(george);
 
     stream_data.set_subscribers(sub, [fred.user_id, george.user_id]);
+    stream_data.update_calculated_fields(sub);
     assert(stream_data.user_is_subscribed('Rome', 'FRED@zulip.com'));
     assert(stream_data.user_is_subscribed('Rome', 'fred@zulip.com'));
     assert(stream_data.user_is_subscribed('Rome', 'george@zulip.com'));
@@ -247,8 +248,17 @@ zrequire('marked', 'third/marked/lib/marked');
 
     // Verify that we noop and don't crash when unsubscribed.
     sub.subscribed = false;
+    stream_data.update_calculated_fields(sub);
     ok = stream_data.add_subscriber('Rome', brutus.user_id);
     assert(ok);
+    assert.equal(stream_data.user_is_subscribed('Rome', email), true);
+    stream_data.remove_subscriber('Rome', brutus.user_id);
+    assert.equal(stream_data.user_is_subscribed('Rome', email), false);
+    stream_data.add_subscriber('Rome', brutus.user_id);
+    assert.equal(stream_data.user_is_subscribed('Rome', email), true);
+
+    sub.invite_only = true;
+    stream_data.update_calculated_fields(sub);
     assert.equal(stream_data.user_is_subscribed('Rome', email), undefined);
     stream_data.remove_subscriber('Rome', brutus.user_id);
     assert.equal(stream_data.user_is_subscribed('Rome', email), undefined);

frontend_tests/node_tests/typeahead_helper.js

@@ -7,6 +7,10 @@ zrequire('pm_conversations');
 zrequire('people');
 zrequire('util');
 zrequire('stream_data');
+zrequire('narrow');
+zrequire('hash_util');
+zrequire('marked', 'third/marked/lib/marked');
+var _ = require('node_modules/underscore/underscore.js');
 var th = zrequire('typeahead_helper');
 
 stream_data.create_streams([
@@ -30,6 +34,7 @@ stream_data.create_streams([
         {name: 'Denmark', pin_to_top: true, subscribers: popular, subscribed: true},
         {name: 'dead', pin_to_top: false, subscribers: unpopular, subscribed: true},
     ];
+    _.each(test_streams, stream_data.update_calculated_fields);
 
     global.stream_data.is_active = function (sub) {
         return sub.name !== 'dead';
@@ -50,6 +55,7 @@ stream_data.create_streams([
         {name: 'Denmark', description: 'visiting Denmark', subscribers: popular, subscribed: true},
         {name: 'dead', description: 'dead stream', subscribers: unpopular, subscribed: true},
     ];
+    _.each(test_streams, stream_data.update_calculated_fields);
     test_streams = th.sort_streams(test_streams, 'wr');
     assert.deepEqual(test_streams[0].name, "Docs"); // Description match
     assert.deepEqual(test_streams[1].name, "Denmark"); // Popular stream
@@ -59,13 +65,14 @@ stream_data.create_streams([
 
     // Test sort both subscribed and unsubscribed streams.
     test_streams = [
-        {name: 'Dev', description: 'Some devs', subscribed: true},
+        {name: 'Dev', description: 'Some devs', subscribed: true, subscribers: popular},
-        {name: 'East', description: 'Developing east', subscribed: true},
+        {name: 'East', description: 'Developing east', subscribed: true, subscribers: popular},
-        {name: 'New', description: 'No match', subscribed: true},
+        {name: 'New', description: 'No match', subscribed: true, subscribers: popular},
-        {name: 'Derp', description: 'Always Derping', subscribed: false},
+        {name: 'Derp', description: 'Always Derping', subscribed: false, subscribers: popular},
-        {name: 'Ether', description: 'Destroying ether', subscribed: false},
+        {name: 'Ether', description: 'Destroying ether', subscribed: false, subscribers: popular},
-        {name: 'Mew', description: 'Cat mews', subscribed: false},
+        {name: 'Mew', description: 'Cat mews', subscribed: false, subscribers: popular},
     ];
+    _.each(test_streams, stream_data.update_calculated_fields);
 
     test_streams = th.sort_streams(test_streams, 'd');
     assert.deepEqual(test_streams[0].name, "Dev"); // Subscribed and stream name starts with query
@@ -187,6 +194,11 @@ _.each(matches, function (person) {
     stream_data.add_subscriber("Dev", people.get_user_id(subscriber_email_2));
     stream_data.add_subscriber("Dev", people.get_user_id(subscriber_email_3));
 
+    var dev_sub = stream_data.get_sub("Dev");
+    var linux_sub = stream_data.get_sub("Linux");
+    stream_data.update_calculated_fields(dev_sub);
+    stream_data.update_calculated_fields(linux_sub);
+
     // For spliting based on whether a PM was sent
     global.pm_conversations.set_partner(5);
     global.pm_conversations.set_partner(6);

static/js/stream_data.js

@@ -363,11 +363,10 @@ exports.remove_subscriber = function (stream_name, user_id) {
 
 exports.user_is_subscribed = function (stream_name, user_email) {
     var sub = exports.get_sub(stream_name);
-    if (typeof sub === 'undefined' || !sub.subscribed) {
+    if (typeof sub === 'undefined' || !sub.can_access_subscribers) {
-        // If we don't know about the stream, or we ourselves are not
+        // If we don't know about the stream, or we ourselves can not access subscriber list,
-        // subscribed, we can't keep track of the subscriber list in general,
         // so we return undefined (treated as falsy if not explicitly handled).
-        blueslip.warn("We got a user_is_subscribed call for a non-existent or unsubscribed stream.");
+        blueslip.warn("We got a user_is_subscribed call for a non-existent or inaccessible stream.");
         return;
     }
     var user_id = people.get_user_id(user_email);