Fix being able to import more than allowed number of follows (#15384)

* Fix being able to import more than allowed number of follows

Without this commit, if someone tries importing a second list of accounts to
follow before the first one has been processed, this will queue imports for
the two whole lists, even if they exceed the account's allowed number of
outgoing follows.

This commit changes it so the individual queued imports aren't exempt from
the follow limit check (they remain exempt from the rate-limiting check
though).

* Catch validation errors to not re-queue failed follows

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

11 files changed, 38 insertions, 16 deletions

diff --git a/app/models/concerns/account_interactions.rb b/app/models/concerns/account_interactions.rb
index e2c4b8acf..974f57820 100644
--- a/app/models/concerns/account_interactions.rb
+++ b/app/models/concerns/account_interactions.rb
@@ -97,8 +97,8 @@ module AccountInteractions
     has_many :announcement_mutes, dependent: :destroy
   end
 
-  def follow!(other_account, reblogs: nil, notify: nil, uri: nil, rate_limit: false)
-    rel = active_relationships.create_with(show_reblogs: reblogs.nil? ? true : reblogs, notify: notify.nil? ? false : notify, uri: uri, rate_limit: rate_limit)
+  def follow!(other_account, reblogs: nil, notify: nil, uri: nil, rate_limit: false, bypass_limit: false)
+    rel = active_relationships.create_with(show_reblogs: reblogs.nil? ? true : reblogs, notify: notify.nil? ? false : notify, uri: uri, rate_limit: rate_limit, bypass_follow_limit: bypass_limit)
                               .find_or_create_by!(target_account: other_account)
 
     rel.show_reblogs = reblogs unless reblogs.nil?
@@ -111,8 +111,8 @@ module AccountInteractions
     rel
   end
 
-  def request_follow!(other_account, reblogs: nil, notify: nil, uri: nil, rate_limit: false)
-    rel = follow_requests.create_with(show_reblogs: reblogs.nil? ? true : reblogs, notify: notify.nil? ? false : notify, uri: uri, rate_limit: rate_limit)
+  def request_follow!(other_account, reblogs: nil, notify: nil, uri: nil, rate_limit: false, bypass_limit: false)
+    rel = follow_requests.create_with(show_reblogs: reblogs.nil? ? true : reblogs, notify: notify.nil? ? false : notify, uri: uri, rate_limit: rate_limit, bypass_follow_limit: bypass_limit)
                          .find_or_create_by!(target_account: other_account)
 
     rel.show_reblogs = reblogs unless reblogs.nil?
diff --git a/app/models/concerns/follow_limitable.rb b/app/models/concerns/follow_limitable.rb
new file mode 100644
index 000000000..c64060d6e
--- /dev/null
+++ b/app/models/concerns/follow_limitable.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+module FollowLimitable
+  extend ActiveSupport::Concern
+
+  included do
+    validates_with FollowLimitValidator, on: :create, unless: :bypass_follow_limit?
+  end
+
+  def bypass_follow_limit=(value)
+    @bypass_follow_limit = value
+  end
+
+  def bypass_follow_limit?
+    @bypass_follow_limit
+  end
+end
diff --git a/app/models/follow.rb b/app/models/follow.rb
index 69a1722b3..a5e3fe809 100644
--- a/app/models/follow.rb
+++ b/app/models/follow.rb
@@ -17,6 +17,7 @@ class Follow < ApplicationRecord
   include Paginable
   include RelationshipCacheable
   include RateLimitable
+  include FollowLimitable
 
   rate_limit by: :account, family: :follows
 
@@ -26,7 +27,6 @@ class Follow < ApplicationRecord
   has_one :notification, as: :activity, dependent: :destroy
 
   validates :account_id, uniqueness: { scope: :target_account_id }
-  validates_with FollowLimitValidator, on: :create, if: :rate_limit?
 
   scope :recent, -> { reorder(id: :desc) }
 
diff --git a/app/models/follow_request.rb b/app/models/follow_request.rb
index 2d2a77b59..59fefcdf6 100644
--- a/app/models/follow_request.rb
+++ b/app/models/follow_request.rb
@@ -17,6 +17,7 @@ class FollowRequest < ApplicationRecord
   include Paginable
   include RelationshipCacheable
   include RateLimitable
+  include FollowLimitable
 
   rate_limit by: :account, family: :follows
 
@@ -26,7 +27,6 @@ class FollowRequest < ApplicationRecord
   has_one :notification, as: :activity, dependent: :destroy
 
   validates :account_id, uniqueness: { scope: :target_account_id }
-  validates_with FollowLimitValidator, on: :create, if: :rate_limit?
 
   def authorize!
     account.follow!(target_account, reblogs: show_reblogs, notify: notify, uri: uri)
diff --git a/app/services/follow_service.rb b/app/services/follow_service.rb
index 962572851..b98f7011d 100644
--- a/app/services/follow_service.rb
+++ b/app/services/follow_service.rb
@@ -11,11 +11,12 @@ class FollowService < BaseService
   # @option [Boolean] :reblogs Whether or not to show reblogs, defaults to true
   # @option [Boolean] :notify Whether to create notifications about new posts, defaults to false
   # @option [Boolean] :bypass_locked
+  # @option [Boolean] :bypass_limit Allow following past the total follow number
   # @option [Boolean] :with_rate_limit
   def call(source_account, target_account, options = {})
     @source_account = source_account
     @target_account = ResolveAccountService.new.call(target_account, skip_webfinger: true)
-    @options        = { bypass_locked: false, with_rate_limit: false }.merge(options)
+    @options        = { bypass_locked: false, bypass_limit: false, with_rate_limit: false }.merge(options)
 
     raise ActiveRecord::RecordNotFound if following_not_possible?
     raise Mastodon::NotPermittedError  if following_not_allowed?
@@ -54,7 +55,7 @@ class FollowService < BaseService
   end
 
   def request_follow!
-    follow_request = @source_account.request_follow!(@target_account, reblogs: @options[:reblogs], notify: @options[:notify], rate_limit: @options[:with_rate_limit])
+    follow_request = @source_account.request_follow!(@target_account, reblogs: @options[:reblogs], notify: @options[:notify], rate_limit: @options[:with_rate_limit], bypass_limit: @options[:bypass_limit])
 
     if @target_account.local?
       LocalNotificationWorker.perform_async(@target_account.id, follow_request.id, follow_request.class.name, :follow_request)
@@ -66,7 +67,7 @@ class FollowService < BaseService
   end
 
   def direct_follow!
-    follow = @source_account.follow!(@target_account, reblogs: @options[:reblogs], notify: @options[:notify], rate_limit: @options[:with_rate_limit])
+    follow = @source_account.follow!(@target_account, reblogs: @options[:reblogs], notify: @options[:notify], rate_limit: @options[:with_rate_limit], bypass_limit: @options[:bypass_limit])
 
     LocalNotificationWorker.perform_async(@target_account.id, follow.id, follow.class.name, :follow)
     MergeWorker.perform_async(@target_account.id, @source_account.id)
diff --git a/app/workers/authorize_follow_worker.rb b/app/workers/authorize_follow_worker.rb
index 0d5014624..f57900fa5 100644
--- a/app/workers/authorize_follow_worker.rb
+++ b/app/workers/authorize_follow_worker.rb
@@ -7,7 +7,7 @@ class AuthorizeFollowWorker
     source_account = Account.find(source_account_id)
     target_account = Account.find(target_account_id)
 
-    AuthorizeFollowService.new.call(source_account, target_account)
+    AuthorizeFollowService.new.call(source_account, target_account, bypass_limit: true)
   rescue ActiveRecord::RecordNotFound
     true
   end
diff --git a/app/workers/import/relationship_worker.rb b/app/workers/import/relationship_worker.rb
index 4a455f3ae..4a7100435 100644
--- a/app/workers/import/relationship_worker.rb
+++ b/app/workers/import/relationship_worker.rb
@@ -15,7 +15,11 @@ class Import::RelationshipWorker
 
     case relationship
     when 'follow'
-      FollowService.new.call(from_account, target_account, options)
+      begin
+        FollowService.new.call(from_account, target_account, options)
+      rescue ActiveRecord::RecordInvalid
+        raise if FollowLimitValidator.limit_for_account(from_account) < from_account.following_count
+      end
     when 'unfollow'
       UnfollowService.new.call(from_account, target_account)
     when 'block'
diff --git a/app/workers/refollow_worker.rb b/app/workers/refollow_worker.rb
index 98940680d..319b00109 100644
--- a/app/workers/refollow_worker.rb
+++ b/app/workers/refollow_worker.rb
@@ -19,7 +19,7 @@ class RefollowWorker
 
       # Schedule re-follow
       begin
-        FollowService.new.call(follower, target_account, reblogs: reblogs, notify: notify)
+        FollowService.new.call(follower, target_account, reblogs: reblogs, notify: notify, bypass_limit: true)
       rescue Mastodon::NotPermittedError, ActiveRecord::RecordNotFound, Mastodon::UnexpectedResponseError, HTTP::Error, OpenSSL::SSL::SSLError
         next
       end
diff --git a/app/workers/unfollow_follow_worker.rb b/app/workers/unfollow_follow_worker.rb
index 71b5a0e3f..0bd5ff472 100644
--- a/app/workers/unfollow_follow_worker.rb
+++ b/app/workers/unfollow_follow_worker.rb
@@ -14,7 +14,7 @@ class UnfollowFollowWorker
     reblogs = follow&.show_reblogs?
     notify  = follow&.notify?
 
-    FollowService.new.call(follower_account, new_target_account, reblogs: reblogs, notify: notify, bypass_locked: bypass_locked)
+    FollowService.new.call(follower_account, new_target_account, reblogs: reblogs, notify: notify, bypass_locked: bypass_locked, bypass_limit: true)
     UnfollowService.new.call(follower_account, old_target_account, skip_unmerge: true)
   rescue ActiveRecord::RecordNotFound, Mastodon::NotPermittedError
     true
diff --git a/lib/mastodon/accounts_cli.rb b/lib/mastodon/accounts_cli.rb
index cdd1db995..653bfca30 100644
--- a/lib/mastodon/accounts_cli.rb
+++ b/lib/mastodon/accounts_cli.rb
@@ -384,7 +384,7 @@ module Mastodon
       end
 
       processed, = parallelize_with_progress(Account.local.without_suspended) do |account|
-        FollowService.new.call(account, target_account)
+        FollowService.new.call(account, target_account, bypass_limit: true)
       end
 
       say("OK, followed target from #{processed} accounts", :green)
diff --git a/spec/workers/refollow_worker_spec.rb b/spec/workers/refollow_worker_spec.rb
index 6b4c04291..df6731b64 100644
--- a/spec/workers/refollow_worker_spec.rb
+++ b/spec/workers/refollow_worker_spec.rb
@@ -23,8 +23,8 @@ describe RefollowWorker do
       result = subject.perform(account.id)
 
       expect(result).to be_nil
-      expect(service).to have_received(:call).with(alice, account, reblogs: true, notify: false)
-      expect(service).to have_received(:call).with(bob, account, reblogs: false, notify: false)
+      expect(service).to have_received(:call).with(alice, account, reblogs: true, notify: false, bypass_limit: true)
+      expect(service).to have_received(:call).with(bob, account, reblogs: false, notify: false, bypass_limit: true)
     end
   end
 end