squash! 4058381b

trx_write_serialisation_history(): Move some code from
trx_purge_add_undo_to_history().

storage/innobase/trx/trx0purge.cc

@@ -268,12 +268,7 @@ trx_purge_add_undo_to_history(const trx_t* trx, trx_undo_t*& undo, mtr_t* mtr)
 
   ut_ad(mach_read_from_2(undo_header + TRX_UNDO_NEEDS_PURGE) <= 1);
   ut_ad(rseg->needs_purge > trx->id);
-
-  if (rseg->last_page_no == FIL_NULL)
-  {
-    rseg->last_page_no= undo->hdr_page_no;
-    rseg->set_last_commit(undo->hdr_offset, trx->rw_trx_hash_element->no);
-  }
+  ut_ad(rseg->last_page_no != FIL_NULL);
 
   rseg->history_size++;
 

storage/innobase/trx/trx0trx.cc

@@ -992,12 +992,14 @@ static void trx_write_serialisation_history(trx_t *trx, mtr_t *mtr)
     {
       mysql_mutex_lock(&purge_sys.pq_mutex);
       trx_sys.assign_new_trx_no(trx);
+      const trx_id_t end{trx->rw_trx_hash_element->no};
       /* If the rollback segment is not empty, trx->no cannot be less
       than any trx_t::no already in rseg. User threads only produce
       events when a rollback segment is empty. */
-      purge_sys.purge_queue.push(TrxUndoRsegs(trx->rw_trx_hash_element->no,
-                                              *rseg));
+      purge_sys.purge_queue.push(TrxUndoRsegs{end, *rseg});
       mysql_mutex_unlock(&purge_sys.pq_mutex);
+      rseg->last_page_no= undo->hdr_page_no;
+      rseg->set_last_commit(undo->hdr_offset, end);
     }
     else
       trx_sys.assign_new_trx_no(trx);