6 files changed, 63 insertions, 32 deletions
diff --git a/app/lib/activitypub/activity/create.rb b/app/lib/activitypub/activity/create.rb
index 000b77df5..e69193b71 100644
--- a/app/lib/activitypub/activity/create.rb
+++ b/app/lib/activitypub/activity/create.rb
@@ -189,22 +189,25 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
     media_attachments = []
 
     as_array(@object['attachment']).each do |attachment|
-      next if attachment['url'].blank?
+      next if attachment['url'].blank? || media_attachments.size >= 4
 
-      href             = Addressable::URI.parse(attachment['url']).normalize.to_s
-      media_attachment = MediaAttachment.create(account: @account, remote_url: href, description: attachment['name'].presence, focus: attachment['focalPoint'], blurhash: supported_blurhash?(attachment['blurhash']) ? attachment['blurhash'] : nil)
-      media_attachments << media_attachment
+      begin
+        href             = Addressable::URI.parse(attachment['url']).normalize.to_s
+        media_attachment = MediaAttachment.create(account: @account, remote_url: href, description: attachment['name'].presence, focus: attachment['focalPoint'], blurhash: supported_blurhash?(attachment['blurhash']) ? attachment['blurhash'] : nil)
+        media_attachments << media_attachment
 
-      next if unsupported_media_type?(attachment['mediaType']) || skip_download?
+        next if unsupported_media_type?(attachment['mediaType']) || skip_download?
 
-      media_attachment.file_remote_url = href
-      media_attachment.save
+        media_attachment.file_remote_url = href
+        media_attachment.save
+      rescue Mastodon::UnexpectedResponseError, HTTP::TimeoutError, HTTP::ConnectionError, OpenSSL::SSL::SSLError
+        RedownloadMediaWorker.perform_in(rand(30..600).seconds, media_attachment.id)
+      end
     end
 
     media_attachments
   rescue Addressable::URI::InvalidURIError => e
-    Rails.logger.debug e
-
+    Rails.logger.debug "Invalid URL in attachment: #{e}"
     media_attachments
   end
 
@@ -405,15 +408,7 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
   end
 
   def check_for_spam
-    spam_check = SpamCheck.new(@status)
-
-    return if spam_check.skip?
-
-    if spam_check.spam?
-      spam_check.flag!
-    else
-      spam_check.remember!
-    end
+    SpamCheck.perform(@status)
   end
 
   def forward_for_reply
diff --git a/app/lib/activitypub/activity/delete.rb b/app/lib/activitypub/activity/delete.rb
index 345060462..dc9ff580c 100644
--- a/app/lib/activitypub/activity/delete.rb
+++ b/app/lib/activitypub/activity/delete.rb
@@ -13,8 +13,7 @@ class ActivityPub::Activity::Delete < ActivityPub::Activity
 
   def delete_person
     lock_or_return("delete_in_progress:#{@account.id}") do
-      SuspendAccountService.new.call(@account)
-      @account.destroy!
+      SuspendAccountService.new.call(@account, reserve_username: false)
     end
   end
 
diff --git a/app/lib/activitypub/activity/move.rb b/app/lib/activitypub/activity/move.rb
index d7a5f595c..6c6a2b967 100644
--- a/app/lib/activitypub/activity/move.rb
+++ b/app/lib/activitypub/activity/move.rb
@@ -10,10 +10,13 @@ class ActivityPub::Activity::Move < ActivityPub::Activity
 
     target_account = ActivityPub::FetchRemoteAccountService.new.call(target_uri)
 
-    return if target_account.nil? || !target_account.also_known_as.include?(origin_account.uri)
+    if target_account.nil? || target_account.suspended? || !target_account.also_known_as.include?(origin_account.uri)
+      unmark_as_processing!
+      return
+    end
 
     # In case for some reason we didn't have a redirect for the profile already, set it
-    origin_account.update(moved_to_account: target_account) if origin_account.moved_to_account_id.nil?
+    origin_account.update(moved_to_account: target_account)
 
     # Initiate a re-follow for each follower
     origin_account.followers.local.select(:id).find_in_batches do |follower_accounts|
@@ -40,4 +43,8 @@ class ActivityPub::Activity::Move < ActivityPub::Activity
   def mark_as_processing!
     redis.setex("move_in_progress:#{@account.id}", PROCESSING_COOLDOWN, true)
   end
+
+  def unmark_as_processing!
+    redis.del("move_in_progress:#{@account.id}")
+  end
 end
diff --git a/app/lib/formatter.rb b/app/lib/formatter.rb
index d85a333b3..4fa053744 100644
--- a/app/lib/formatter.rb
+++ b/app/lib/formatter.rb
@@ -115,8 +115,7 @@ class Formatter
   end
 
   def format_field(account, str, **options)
-    return reformat(str).html_safe unless account.local? # rubocop:disable Rails/OutputSafety
-    html = encode_and_link_urls(str, me: true)
+    html = account.local? ? encode_and_link_urls(str, me: true) : reformat(str)
     html = encode_custom_emojis(html, account.emojis, options[:autoplay]) if options[:custom_emojify]
     html.html_safe # rubocop:disable Rails/OutputSafety
   end
diff --git a/app/lib/settings/scoped_settings.rb b/app/lib/settings/scoped_settings.rb
index 343996e8a..4d21e0de7 100644
--- a/app/lib/settings/scoped_settings.rb
+++ b/app/lib/settings/scoped_settings.rb
@@ -5,6 +5,7 @@ module Settings
     DEFAULTING_TO_UNSCOPED = %w(
       flavour
       skin
+      noindex
     ).freeze
 
     def initialize(object)
diff --git a/app/lib/spam_check.rb b/app/lib/spam_check.rb
index 0cf1b8790..441697364 100644
--- a/app/lib/spam_check.rb
+++ b/app/lib/spam_check.rb
@@ -4,9 +4,25 @@ class SpamCheck
   include Redisable
   include ActionView::Helpers::TextHelper
 
+  # Threshold over which two Nilsimsa values are considered
+  # to refer to the same text
   NILSIMSA_COMPARE_THRESHOLD = 95
-  NILSIMSA_MIN_SIZE          = 10
-  EXPIRE_SET_AFTER           = 1.week.seconds
+
+  # Nilsimsa doesn't work well on small inputs, so below
+  # this size, we check only for exact matches with MD5
+  NILSIMSA_MIN_SIZE = 10
+
+  # How long to keep the trail of digests between updates,
+  # there is no reason to store it forever
+  EXPIRE_SET_AFTER = 1.week.seconds
+
+  # How many digests to keep in an account's trail. If it's
+  # too small, spam could rotate around different message templates
+  MAX_TRAIL_SIZE = 10
+
+  # How many detected duplicates to allow through before
+  # considering the message as spam
+  THRESHOLD = 5
 
   def initialize(status)
     @account = status.account
@@ -21,9 +37,9 @@ class SpamCheck
     if insufficient_data?
       false
     elsif nilsimsa?
-      any_other_digest?('nilsimsa') { |_, other_digest| nilsimsa_compare_value(digest, other_digest) >= NILSIMSA_COMPARE_THRESHOLD }
+      digests_over_threshold?('nilsimsa') { |_, other_digest| nilsimsa_compare_value(digest, other_digest) >= NILSIMSA_COMPARE_THRESHOLD }
     else
-      any_other_digest?('md5') { |_, other_digest| other_digest == digest }
+      digests_over_threshold?('md5') { |_, other_digest| other_digest == digest }
     end
   end
 
@@ -38,7 +54,7 @@ class SpamCheck
     # get the correct status ID back, we have to save it in the string value
 
     redis.zadd(redis_key, @status.id, digest_with_algorithm)
-    redis.zremrangebyrank(redis_key, '0', '-10')
+    redis.zremrangebyrank(redis_key, 0, -(MAX_TRAIL_SIZE + 1))
     redis.expire(redis_key, EXPIRE_SET_AFTER)
   end
 
@@ -78,6 +94,20 @@ class SpamCheck
     end
   end
 
+  class << self
+    def perform(status)
+      spam_check = new(status)
+
+      return if spam_check.skip?
+
+      if spam_check.spam?
+        spam_check.flag!
+      else
+        spam_check.remember!
+      end
+    end
+  end
+
   private
 
   def disabled?
@@ -149,14 +179,14 @@ class SpamCheck
     redis.zrange(redis_key, 0, -1)
   end
 
-  def any_other_digest?(filter_algorithm)
-    other_digests.any? do |record|
+  def digests_over_threshold?(filter_algorithm)
+    other_digests.select do |record|
       algorithm, other_digest, status_id = record.split(':')
 
       next unless algorithm == filter_algorithm
 
       yield algorithm, other_digest, status_id
-    end
+    end.size >= THRESHOLD
   end
 
   def matching_status_ids