Change artefact attachment upgrade to create mysql index names correctly

htdocs/lib/db/upgrade.php

@@ -926,14 +926,12 @@ function xmldb_core_upgrade($oldversion=0) {
             execute_sql("ALTER TABLE {artefact_attachment} DROP FOREIGN KEY {arteblogblogfile_blo_fk}");
             execute_sql("ALTER TABLE {artefact_attachment} DROP INDEX {arteblogblogfile_blo_ix}");
             execute_sql("ALTER TABLE {artefact_attachment} CHANGE blogpost artefact BIGINT(10) DEFAULT NULL");
-            execute_sql("ALTER TABLE {artefact_attachment} ADD INDEX {artefact_attchment_art_ix} (artefact)");
-            execute_sql("ALTER TABLE {artefact_attachment} ADD FOREIGN KEY(artefact) REFERENCES {artefact}(id)");
+            execute_sql("ALTER TABLE {artefact_attachment} ADD CONSTRAINT {arteatta_art_fk} FOREIGN KEY {arteatta_art_ix} (artefact) REFERENCES {artefact}(id)");
 
             execute_sql("ALTER TABLE {artefact_attachment} DROP FOREIGN KEY {arteblogblogfile_fil_fk}");
             execute_sql("ALTER TABLE {artefact_attachment} DROP INDEX {arteblogblogfile_fil_ix}");
             execute_sql("ALTER TABLE {artefact_attachment} CHANGE file attachment BIGINT(10) DEFAULT NULL");
-            execute_sql("ALTER TABLE {artefact_attachment} ADD INDEX {artefact_attchment_att_ix} (attachment)");
-            execute_sql("ALTER TABLE {artefact_attachment} ADD FOREIGN KEY(attachment) REFERENCES {artefact}(id)");
+            execute_sql("ALTER TABLE {artefact_attachment} ADD CONSTRAINT {arteatta_att_fk} FOREIGN KEY {arteatta_att_ix} (attachment) REFERENCES {artefact}(id)");
         }
 
         // Drop the _pending table. From now on files uploaded as attachments will become artefacts