MDEV-15374 Server hangs and aborts with long semaphore wait or assertion `len...

MDEV-15374 Server hangs and aborts with long semaphore wait or assertion `len < ((ulint) srv_page_size)' fails in trx_undo_rec_copy upon ROLLBACK on temporary table

Problem:
=======
InnoDB cleans all temporary undo logs during commit. During rollback
of secondary index entry, InnoDB tries to build the previous version
of clustered index. It leads to access of freed undo page during
previous transaction commit and it leads to undo log corruption.

Solution:
=========
During rollback, temporary undo logs should not try to build
the previous version of the record.

storage/innobase/row/row0umod.cc

@@ -428,7 +428,7 @@ row_undo_mod_del_mark_or_remove_sec_low(
 	btr_pcur_t		pcur;
 	btr_cur_t*		btr_cur;
 	ibool			success;
-	ibool			old_has;
+	ibool			old_has = FALSE;
 	dberr_t			err	= DB_SUCCESS;
 	mtr_t			mtr;
 	mtr_t			mtr_vers;
@@ -504,10 +504,15 @@ row_undo_mod_del_mark_or_remove_sec_low(
 					    &mtr_vers);
 	ut_a(success);
 
-	old_has = row_vers_old_has_index_entry(FALSE,
-					       btr_pcur_get_rec(&(node->pcur)),
-					       &mtr_vers, index, entry,
-					       0, 0);
+	/* For temporary table, we can skip to check older version of
+	clustered index entry. Because the purge won't process
+	any no-redo rollback segment undo logs. */
+	if (!dict_table_is_temporary(node->table)) {
+		old_has = row_vers_old_has_index_entry(
+				FALSE, btr_pcur_get_rec(&(node->pcur)),
+				&mtr_vers, index, entry, 0, 0);
+	}
+
 	if (old_has) {
 		err = btr_cur_del_mark_set_sec_rec(BTR_NO_LOCKING_FLAG,
 						   btr_cur, TRUE, thr, &mtr);

storage/innobase/trx/trx0rec.cc

@@ -2087,13 +2087,11 @@ trx_undo_report_row_operation(
 
 /** Copy an undo record to heap.
 @param[in]	roll_ptr	roll pointer to a record that exists
-@param[in]	is_temp		whether this is a temporary table
 @param[in,out]	heap		memory heap where copied */
 static
 trx_undo_rec_t*
 trx_undo_get_undo_rec_low(
 	roll_ptr_t	roll_ptr,
-	bool		is_temp,
 	mem_heap_t*	heap)
 {
 	trx_undo_rec_t*	undo_rec;
@@ -2109,10 +2107,7 @@ trx_undo_get_undo_rec_low(
 				 &offset);
 	ut_ad(page_no > FSP_FIRST_INODE_PAGE_NO);
 	ut_ad(offset >= TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_HDR_SIZE);
-	rseg = is_temp
-		? trx_sys->temp_rsegs[rseg_id]
-		: trx_sys->rseg_array[rseg_id];
-	ut_ad(is_temp == !rseg->is_persistent());
+	rseg = trx_sys->rseg_array[rseg_id];
 
 	mtr_start(&mtr);
 
@@ -2128,7 +2123,6 @@ trx_undo_get_undo_rec_low(
 
 /** Copy an undo record to heap.
 @param[in]	roll_ptr	roll pointer to record
-@param[in]	is_temp		whether this is a temporary table
 @param[in,out]	heap		memory heap where copied
 @param[in]	trx_id		id of the trx that generated
 				the roll pointer: it points to an
@@ -2143,7 +2137,6 @@ static MY_ATTRIBUTE((warn_unused_result))
 bool
 trx_undo_get_undo_rec(
 	roll_ptr_t		roll_ptr,
-	bool			is_temp,
 	mem_heap_t*		heap,
 	trx_id_t		trx_id,
 	const table_name_t&	name,
@@ -2155,7 +2148,7 @@ trx_undo_get_undo_rec(
 
 	missing_history = purge_sys->view.changes_visible(trx_id, name);
 	if (!missing_history) {
-		*undo_rec = trx_undo_get_undo_rec_low(roll_ptr, is_temp, heap);
+		*undo_rec = trx_undo_get_undo_rec_low(roll_ptr, heap);
 	}
 
 	rw_lock_s_unlock(&purge_sys->latch);
@@ -2236,19 +2229,19 @@ trx_undo_prev_version_build(
 		return(true);
 	}
 
-	const bool is_temp = dict_table_is_temporary(index->table);
+	ut_ad(!dict_table_is_temporary(index->table));
+
 	rec_trx_id = row_get_rec_trx_id(rec, index, offsets);
 
 	ut_ad(!index->table->skip_alter_undo);
 
 	if (trx_undo_get_undo_rec(
-		    roll_ptr, is_temp, heap, rec_trx_id, index->table->name,
+		    roll_ptr, heap, rec_trx_id, index->table->name,
 		    &undo_rec)) {
 		if (v_status & TRX_UNDO_PREV_IN_PURGE) {
 			/* We are fetching the record being purged */
-			ut_ad(!is_temp);
 			undo_rec = trx_undo_get_undo_rec_low(
-				roll_ptr, is_temp, heap);
+				roll_ptr, heap);
 		} else {
 			/* The undo record may already have been purged,
 			during purge or semi-consistent read. */