Allow domain blocks that only reject media without silencing or suspending (#4325)

* Allow domain blocks to reject media without silencing or suspending

* Fix typo

* Hide 'Reject media' button when superfluous, instead of disabling it

* Properly hide 'reject media' checkbox on page load if needed

This may happen when resubmitting the domain block form after an error.

* Don't ask whether undoing a media-only block should be retroactive

* Rename :media_only block to :noop

* Display :noop block as None in frontend, allow blocks that do nothing

* Remove 'coding' line auto-added by emacs

app/models/domain_block.rb

@@ -12,7 +12,7 @@
 #
 
 class DomainBlock < ApplicationRecord
-  enum severity: [:silence, :suspend]
+  enum severity: [:silence, :suspend, :noop]
 
   attr_accessor :retroactive
 

app/services/block_domain_service.rb

@@ -11,16 +11,16 @@ class BlockDomainService < BaseService
   private
 
   def process_domain_block
+    clear_media! if domain_block.reject_media?
     if domain_block.silence?
       silence_accounts!
-    else
+    elsif domain_block.suspend?
       suspend_accounts!
     end
   end
 
   def silence_accounts!
     blocked_domain_accounts.in_batches.update_all(silenced: true)
-    clear_media! if domain_block.reject_media?
   end
 
   def clear_media!

app/services/unblock_domain_service.rb

@@ -10,7 +10,7 @@ class UnblockDomainService < BaseService
   end
 
   def process_retroactive_updates
-    blocked_accounts.in_batches.update_all(update_options)
+    blocked_accounts.in_batches.update_all(update_options) unless domain_block.noop?
   end
 
   def blocked_accounts

app/views/admin/domain_blocks/show.html.haml

@@ -3,6 +3,11 @@
 
 = simple_form_for @domain_block, url: admin_domain_block_path(@domain_block), method: :delete do |f|
 
+  - if (@domain_block.noop?)
+    = f.input :retroactive,
+      as: :hidden,
+      input_html: { :value => "0" }
+  - else
     = f.input :retroactive,
       as: :boolean,
       wrapper: :with_label,

config/locales/en.yml

@@ -108,13 +108,15 @@ en:
         create: Create block
         hint: The domain block will not prevent creation of account entries in the database, but will retroactively and automatically apply specific moderation methods on those accounts.
         severity:
-          desc_html: "<strong>Silence</strong> will make the account's posts invisible to anyone who isn't following them. <strong>Suspend</strong> will remove all of the account's content, media, and profile data."
+          desc_html: "<strong>Silence</strong> will make the account's posts invisible to anyone who isn't following them. <strong>Suspend</strong> will remove all of the account's content, media, and profile data. Use <strong>None</strong> if you just want to reject media files."
+          noop: None
           silence: Silence
           suspend: Suspend
         title: New domain block
       reject_media: Reject media files
       reject_media_hint: Removes locally stored media files and refuses to download any in the future. Irrelevant for suspensions
       severities:
+        noop: None
         silence: Silence
         suspend: Suspend
       severity: Severity