keyword mute: use mentions scope in home feed filtering (#454)

If a status shows up in mentions because all keyword mutes that might
apply to it are marked as "don't apply to mentions", then it ought to
show up in the home feed also.

app/lib/feed_manager.rb

@@ -153,7 +153,7 @@ class FeedManager
   def filter_from_home?(status, receiver_id)
     return false if receiver_id == status.account_id
     return true  if status.reply? && (status.in_reply_to_id.nil? || status.in_reply_to_account_id.nil?)
-    return true if keyword_filter?(status, receiver_id, Glitch::KeywordMute::Scopes::HomeFeed)
+    return true  if keyword_filter_from_home?(status, receiver_id)
 
     check_for_mutes = [status.account_id]
     check_for_mutes.concat(status.mentions.pluck(:account_id))
@@ -182,6 +182,22 @@ class FeedManager
     false
   end
 
+  def keyword_filter_from_home?(status, receiver_id)
+    # If this status mentions the receiver, use the mentions scope: it's
+    # possible that the status will show up in the receiver's mentions, which
+    # means it ought to show up in the home feed as well.
+    #
+    # If it doesn't mention the receiver but is still headed for the home feed,
+    # use the home feed scope.
+    scope = if status.mentions.pluck(:account_id).include?(receiver_id)
+              Glitch::KeywordMute::Scopes::Mentions
+            else
+              Glitch::KeywordMute::Scopes::HomeFeed
+            end
+
+    return true if keyword_filter?(status, receiver_id, scope)
+  end
+
   def keyword_filter?(status, receiver_id, scope)
     Glitch::KeywordMuteHelper.new(receiver_id).matches?(status, scope)
   end

spec/lib/feed_manager_spec.rb

@@ -187,6 +187,14 @@ RSpec.describe FeedManager do
 
         expect(FeedManager.instance.filter?(:home, status, alice.id)).to be true
       end
+
+      it 'returns false if the status is muted by a keyword mute that does not apply to mentions' do
+        Fabricate('Glitch::KeywordMute', account: alice, keyword: 'take', apply_to_mentions: false)
+        status = Fabricate(:status, spoiler_text: 'This is a hot take', account: bob)
+        status.mentions.create!(account_id: alice.id)
+
+        expect(FeedManager.instance.filter?(:home, status, alice.id)).to be false
+      end
     end
 
     context 'for mentions feed' do