[B] Handle packaging paths better when exporting

api/app/jobs/packaging/exportation/export_text_to_epub_v3_job.rb

@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 module Packaging
   module Exportation
     class ExportTextToEpubV3Job < ApplicationJob
-      discard_on ActiveJob::DeserializationError, ActiveRecord::RecordNotFound
+      discard_on ActiveJob::DeserializationError, ActiveRecord::RecordNotFound, Utility::IndexMap::AlreadyStoredObjectError, StandardError
 
       around_perform :advisory_locked!
 
@@ -15,6 +17,12 @@ class ExportTextToEpubV3Job < ApplicationJob
       def perform(text, force: false)
         Packaging::Exportation::ExportTextToEpubV3.run! text: text, force: force
       end
+
+      # We should lock only on the text id.
+      # @return [(String)]
+      def lock_key_arguments
+        [arguments.first.try(:id)]
+      end
     end
   end
 end

api/app/models/text_section.rb

@@ -109,6 +109,34 @@ class TextSection < ApplicationRecord
 
   friendly_id :slug_candidates, use: :scoped, scope: :text
 
+  def has_duplicate_source_identifier?
+    # :nocov:
+    return false if text.blank? || new_record?
+    # :nocov:
+
+    text.text_sections.where.not(id: id).exists?(source_identifier: source_identifier)
+  end
+
+  def has_unique_source_identifier?
+    # :nocov:
+    return false if text.blank? || new_record?
+    # :nocov:
+
+    !has_duplicate_source_identifier?
+  end
+
+  # @!attribute [r] packaging_base_path
+  # @return [String]
+  def packaging_base_path
+    "text/#{packaging_identifier}".gsub(/\A(.+)(?<!\.xhtml)\z/, '\1.xhtml')
+  end
+
+  # @!attribute [r] packaging_identifier
+  # @return [String]
+  def packaging_identifier
+    has_unique_source_identifier? ? source_identifier : slug
+  end
+
   def slug_candidates
     reserved_words = %w(all new edit session login logout users admin
                         stylesheets assets javascripts)

api/app/services/packaging/epub_v3/text_section_item.rb

@@ -52,8 +52,9 @@ def to_io
 
       private
 
+      # @see TextSection#packaging_base_path
       def build_base_path
-        "text/#{text_section.source_identifier}".gsub(/\A(.+)(?<!\.xhtml)\z/, '\1.xhtml')
+        text_section.packaging_base_path
       end
 
       def default_landmark