fix old photos without a remote_photo_path or remote_photo_name

closes #8012

Changelog.md

@@ -4,6 +4,9 @@
 * Enable paranoid mode for devise [#8003](https://github.com/diaspora/diaspora/pull/8003)
 * Refactor likes cucumber test [#8002](https://github.com/diaspora/diaspora/pull/8002)
 
+## Bug fixes
+* Fix old photos without remote url for export [#8012](https://github.com/diaspora/diaspora/pull/8012)
+
 ## Features
 * Add a manifest.json file as a first step to make diaspora\* a Progressive Web App [#7998](https://github.com/diaspora/diaspora/pull/7998)
 * Allow `web+diaspora://` links to link to a profile with only the diaspora ID [#8000](https://github.com/diaspora/diaspora/pull/8000)

db/migrate/20190509125709_fix_missing_remote_photo_fields.rb

+# frozen_string_literal: true
+
+class FixMissingRemotePhotoFields < ActiveRecord::Migration[5.1]
+  def up
+    Photo.where(remote_photo_path: nil).each do |photo|
+      photo.write_attribute(:unprocessed_image, photo.read_attribute(:processed_image))
+      photo.update_remote_path
+      photo.save!
+    end
+  end
+end