Post-fix MDEV-12219 Discard temporary undo logs at transaction commit

row_purge_remove_sec_if_poss_leaf(): Add a debug assertion.

row_purge_parse_undo_rec(): Add a debug assertion that the table cannot
be a temporary table. Remove a dead condition.

storage/innobase/row/row0purge.cc

@@ -412,6 +412,7 @@ row_purge_remove_sec_if_poss_leaf(
 	bool			success	= true;
 
 	log_free_check();
+	ut_ad(index->table == node->table);
 	ut_ad(!dict_table_is_temporary(index->table));
 	mtr_start(&mtr);
 	mtr.set_named_space(index->space);
@@ -855,6 +856,7 @@ row_purge_parse_undo_rec(
 		/* The table has been dropped: no need to do purge */
 		goto err_exit;
 	}
+	ut_ad(!dict_table_is_temporary(node->table));
 
 	if (node->table->n_v_cols && !node->table->vc_templ
 	    && dict_table_has_indexed_v_cols(node->table)) {
@@ -874,12 +876,6 @@ row_purge_parse_undo_rec(
 		innobase_init_vc_templ(node->table);
 	}
 
-	/* Disable purging for temp-tables as they are short-lived
-	and no point in re-organzing such short lived tables */
-	if (dict_table_is_temporary(node->table)) {
-		goto close_exit;
-	}
-
 	if (node->table->ibd_file_missing) {
 		/* We skip purge of missing .ibd files */