Merge remote-tracking branch 'origin/master' into merge-upstream

Conflicts:
 	README.md
 	app/controllers/follower_accounts_controller.rb
 	app/controllers/following_accounts_controller.rb
 	app/serializers/rest/instance_serializer.rb
 	app/views/stream_entries/_simple_status.html.haml
 	config/locales/simple_form.ja.yml

app/controllers/api/v1/timelines/public_controller.rb

@@ -21,15 +21,23 @@ class Api::V1::Timelines::PublicController < Api::BaseController
   end
 
   def public_statuses
-    public_timeline_statuses.paginate_by_max_id(
+    statuses = public_timeline_statuses.paginate_by_max_id(
       limit_param(DEFAULT_STATUSES_LIMIT),
       params[:max_id],
       params[:since_id]
     )
+
+    if truthy_param?(:only_media)
+      # `SELECT DISTINCT id, updated_at` is too slow, so pluck ids at first, and then select id, updated_at with ids.
+      status_ids = statuses.joins(:media_attachments).distinct(:id).pluck(:id)
+      statuses.where(id: status_ids)
+    else
+      statuses
+    end
   end
 
   def public_timeline_statuses
-    Status.as_public_timeline(current_account, params[:local])
+    Status.as_public_timeline(current_account, truthy_param?(:local))
   end
 
   def insert_pagination_headers
@@ -37,7 +45,7 @@ class Api::V1::Timelines::PublicController < Api::BaseController
   end
 
   def pagination_params(core_params)
-    params.permit(:local, :limit).merge(core_params)
+    params.permit(:local, :limit, :only_media).merge(core_params)
   end
 
   def next_path

app/controllers/api/v1/timelines/tag_controller.rb

@@ -29,16 +29,24 @@ class Api::V1::Timelines::TagController < Api::BaseController
     if @tag.nil?
       []
     else
-      tag_timeline_statuses.paginate_by_max_id(
+      statuses = tag_timeline_statuses.paginate_by_max_id(
         limit_param(DEFAULT_STATUSES_LIMIT),
         params[:max_id],
         params[:since_id]
       )
+
+      if truthy_param?(:only_media)
+        # `SELECT DISTINCT id, updated_at` is too slow, so pluck ids at first, and then select id, updated_at with ids.
+        status_ids = statuses.joins(:media_attachments).distinct(:id).pluck(:id)
+        statuses.where(id: status_ids)
+      else
+        statuses
+      end
     end
   end
 
   def tag_timeline_statuses
-    Status.as_tag_timeline(@tag, current_account, params[:local])
+    Status.as_tag_timeline(@tag, current_account, truthy_param?(:local))
   end
 
   def insert_pagination_headers
@@ -46,7 +54,7 @@ class Api::V1::Timelines::TagController < Api::BaseController
   end
 
   def pagination_params(core_params)
-    params.permit(:local, :limit).merge(core_params)
+    params.permit(:local, :limit, :only_media).merge(core_params)
   end
 
   def next_path