DEV: Support phpBB 3.3 imports (#17641)

* handle polls with duplicate items
* handle polls with incorrect poll_option_total values
* handle group IDs in personal messages
* support for version 3.3

script/import_scripts/phpbb3/database/database.rb

@@ -22,13 +22,13 @@ module ImportScripts::PhpBB3
       if version.start_with?('3.0')
         require_relative 'database_3_0'
         Database_3_0.new(@database_client, @database_settings)
-      elsif version.start_with?('3.1') || version.start_with?('3.2')
+      elsif version.start_with?('3.1') || version.start_with?('3.2') || version.start_with?('3.3')
         require_relative 'database_3_1'
         Database_3_1.new(@database_client, @database_settings)
       else
         raise UnsupportedVersionError, <<~TEXT
           Unsupported version (#{version}) of phpBB detected.
-          Currently only version 3.0, 3.1 and 3.2 are supported by this importer.
+          Currently only version 3.0, 3.1, 3.2 and 3.3 are supported by this importer.
         TEXT
       end
     end

script/import_scripts/phpbb3/database/database_3_0.rb

@@ -115,13 +115,13 @@ module ImportScripts::PhpBB3
     def fetch_poll_options(topic_id)
       query(<<-SQL)
         SELECT o.poll_option_id, o.poll_option_text, o.poll_option_total AS total_votes,
-          o.poll_option_total - (
+          GREATEST(CAST(o.poll_option_total AS SIGNED) - (
             SELECT COUNT(DISTINCT v.vote_user_id)
               FROM #{@table_prefix}poll_votes v
                 JOIN #{@table_prefix}users u ON (v.vote_user_id = u.user_id)
                 JOIN #{@table_prefix}topics t ON (v.topic_id = t.topic_id)
               WHERE v.poll_option_id = o.poll_option_id AND v.topic_id = o.topic_id
-          ) AS anonymous_votes
+          ),0) AS anonymous_votes
         FROM #{@table_prefix}poll_options o
         WHERE o.topic_id = #{topic_id}
         ORDER BY o.poll_option_id