Add new upload limit system (fix #4234).

app/models/post.rb

@@ -1279,6 +1279,9 @@ class Post < ApplicationRecord
         # XXX This must happen *after* the `is_deleted` flag is set to true (issue #3419).
         give_favorites_to_parent(options) if options[:move_favorites]
 
+        is_automatic = (reason == "Unapproved in three days")
+        uploader.new_upload_limit.update_limit!(self, incremental: is_automatic)
+
         unless options[:without_mod_action]
           ModAction.log("deleted post ##{id}, reason: #{reason}", :post_delete)
         end

app/models/post_approval.rb

@@ -26,10 +26,13 @@ class PostApproval < ApplicationRecord
   end
 
   def approve_post
-    ModAction.log("undeleted post ##{post_id}", :post_undelete) if post.is_deleted
+    is_undeletion = post.is_deleted
 
     post.flags.each(&:resolve!)
     post.update(approver: user, is_flagged: false, is_pending: false, is_deleted: false)
+    ModAction.log("undeleted post ##{post_id}", :post_undelete) if is_undeletion
+
+    post.uploader.new_upload_limit.update_limit!(post, incremental: !is_undeletion)
   end
 
   def self.search(params)

app/models/user.rb

@@ -468,6 +468,10 @@ class User < ApplicationRecord
       (is_moderator? && flag.not_uploaded_by?(id)) || flag.creator_id == id
     end
 
+    def new_upload_limit
+      @new_upload_limit ||= UploadLimit.new(self)
+    end
+
     def upload_limit
       [max_upload_limit - used_upload_slots, 0].max
     end