add bulk placeholder

lib/submissions/create_from_submitters.rb

@@ -7,7 +7,7 @@ module Submissions
     def call(template:, user:, submissions_attrs:, source:, submitters_order:, mark_as_sent: false, params: {})
       preferences = Submitters.normalize_preferences(user.account, user, params)
 
-      Array.wrap(submissions_attrs).map do |attrs|
+      Array.wrap(submissions_attrs).filter_map do |attrs|
         submission_preferences = Submitters.normalize_preferences(user.account, user, attrs)
         submission_preferences = preferences.merge(submission_preferences)
 
@@ -36,6 +36,8 @@ module Submissions
                           preferences: preferences.merge(submission_preferences))
         end
 
+        next if submission.submitters.blank?
+
         submission.tap(&:save!)
       end
     end

lib/submissions/generate_result_attachments.rb

@@ -43,7 +43,7 @@ module Submissions
 
       template = submitter.submission.template
 
-      account = submitter.submission.template.account
+      account = submitter.account
       pkcs = Accounts.load_signing_pkcs(account)
       tsa_url = Accounts.load_timeserver_url(account)
       attachments_data_cache = {}