Restructure pg_upgrade checks because pre-8.4 Postgres did not rename

toast file names to match the new relfilenode.

contrib/pg_upgrade/info.c

@@ -51,9 +51,18 @@ gen_db_file_maps(DbInfo *old_db, DbInfo *new_db,
 		RelInfo    *new_rel = &new_db->rel_arr.rels[relnum];
 
 		if (old_rel->reloid != new_rel->reloid)
-			pg_log(PG_FATAL, "mismatch of relation id: database \"%s\", old relid %d, new relid %d\n",
+			pg_log(PG_FATAL, "Mismatch of relation id: database \"%s\", old relid %d, new relid %d\n",
 			old_db->db_name, old_rel->reloid, new_rel->reloid);
-	
+
+		/* toast names were not renamed to match their relfilenodes in pre-8.4 */
+		if (GET_MAJOR_VERSION(old_cluster.major_version) >= 804 &&
+			(strcmp(old_rel->nspname, new_rel->nspname) != 0 ||
+		     strcmp(old_rel->relname, new_rel->relname) != 0))
+			pg_log(PG_FATAL, "Mismatch of relation names: database \"%s\", "
+				"old rel %s.%s, new rel %s.%s\n",
+				old_db->db_name, old_rel->nspname, old_rel->relname,
+				new_rel->nspname, new_rel->relname);
+
 		create_rel_filename_map(old_pgdata, new_pgdata, old_db, new_db,
 				old_rel, new_rel, maps + num_maps);
 		num_maps++;
@@ -104,12 +113,6 @@ create_rel_filename_map(const char *old_data, const char *new_data,
 	/* new_relfilenode will match old and new pg_class.oid */
 	map->new_relfilenode = new_rel->relfilenode;
 
-	if (strcmp(old_rel->nspname, new_rel->nspname) != 0 ||
-	    strcmp(old_rel->relname, new_rel->relname) != 0)
-		pg_log(PG_FATAL, "mismatch of relation id: database \"%s\", old rel %s.%s, new rel %s.%s\n",
-			old_db->db_name, old_rel->nspname, old_rel->relname,
-			new_rel->nspname, new_rel->relname);
-
 	/* used only for logging and error reporing, old/new are identical */
 	snprintf(map->nspname, sizeof(map->nspname), "%s", old_rel->nspname);
 	snprintf(map->relname, sizeof(map->relname), "%s", old_rel->relname);