diff --git a/mysql-test/suite/innodb/r/xa_recovery_debug.result b/mysql-test/suite/innodb/r/xa_recovery_debug.result
index 082fc96e198..0a035937b9c 100644
--- a/mysql-test/suite/innodb/r/xa_recovery_debug.result
+++ b/mysql-test/suite/innodb/r/xa_recovery_debug.result
@@ -12,7 +12,7 @@ COUNT(*)
 2
 XA END 'zombie';
 XA PREPARE 'zombie';
-SET DEBUG_SYNC='trx_xa_rollback SIGNAL s1 WAIT_FOR s2';
+SET DEBUG_SYNC='trx_after_rollback_row SIGNAL s1 WAIT_FOR s2';
 XA ROLLBACK 'zombie';
 connection default;
 SET DEBUG_SYNC='now WAIT_FOR s1';
@@ -21,7 +21,6 @@ DELETE FROM t LIMIT 1;
 disconnect con1;
 XA COMMIT 'zombie';
 ERROR XAE04: XAER_NOTA: Unknown XID
-SELECT COUNT(*) FROM t;
-COUNT(*)
-0
+SELECT * FROM t;
+a	b
 DROP TABLE t;
diff --git a/mysql-test/suite/innodb/t/xa_recovery_debug.test b/mysql-test/suite/innodb/t/xa_recovery_debug.test
index 8b1f188a0e3..21a38854adb 100644
--- a/mysql-test/suite/innodb/t/xa_recovery_debug.test
+++ b/mysql-test/suite/innodb/t/xa_recovery_debug.test
@@ -17,7 +17,7 @@ UPDATE t SET b=1 WHERE a=1;
 SELECT COUNT(*) FROM t;
 XA END 'zombie';
 XA PREPARE 'zombie';
-SET DEBUG_SYNC='trx_xa_rollback SIGNAL s1 WAIT_FOR s2';
+SET DEBUG_SYNC='trx_after_rollback_row SIGNAL s1 WAIT_FOR s2';
 --send XA ROLLBACK 'zombie'
 connection default;
 SET DEBUG_SYNC='now WAIT_FOR s1';
@@ -29,7 +29,11 @@ DELETE FROM t LIMIT 1;
 let $shutdown_timeout=0;
 --source include/restart_mysqld.inc
 disconnect con1;
+# If the trx_undo_set_state_at_prepare() is omitted at the start of
+# XA ROLLBACK, then the XA COMMIT would succeed and the table would
+# incorrectly show the result of the INSERT but not the UPDATE,
+# because we would commit a partially rolled back transaction.
 --error ER_XAER_NOTA
 XA COMMIT 'zombie';
-SELECT COUNT(*) FROM t;
+SELECT * FROM t;
 DROP TABLE t;
diff --git a/storage/innobase/row/row0undo.cc b/storage/innobase/row/row0undo.cc
index 109bf1004ca..11b775da376 100644
--- a/storage/innobase/row/row0undo.cc
+++ b/storage/innobase/row/row0undo.cc
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1997, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, 2019, MariaDB Corporation.
+Copyright (c) 2017, 2020, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -350,6 +350,12 @@ row_undo_step(
 
 	err = row_undo(node, thr);
 
+#ifdef ENABLED_DEBUG_SYNC
+	if (trx->mysql_thd) {
+		DEBUG_SYNC_C("trx_after_rollback_row");
+	}
+#endif /* ENABLED_DEBUG_SYNC */
+
 	trx->error_state = err;
 
 	if (err != DB_SUCCESS) {
diff --git a/storage/innobase/trx/trx0roll.cc b/storage/innobase/trx/trx0roll.cc
index 20798323802..b6d7aa9f380 100644
--- a/storage/innobase/trx/trx0roll.cc
+++ b/storage/innobase/trx/trx0roll.cc
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1996, 2017, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2016, 2019, MariaDB Corporation.
+Copyright (c) 2016, 2020, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -200,10 +200,21 @@ dberr_t trx_rollback_for_mysql(trx_t* trx)
 	case TRX_STATE_PREPARED_RECOVERED:
 		ut_ad(!trx_is_autocommit_non_locking(trx));
 		if (trx->has_logged_persistent()) {
-			/* Change the undo log state back from
-			TRX_UNDO_PREPARED to TRX_UNDO_ACTIVE
-			so that if the system gets killed,
-			recovery will perform the rollback. */
+			/* The XA ROLLBACK of a XA PREPARE transaction
+			will consist of multiple mini-transactions.
+
+			As the very first step of XA ROLLBACK, we must
+			change the undo log state back from
+			TRX_UNDO_PREPARED to TRX_UNDO_ACTIVE, in order
+			to ensure that recovery will complete the
+			rollback.
+
+			Failure to perform this step could cause a
+			situation where we would roll back part of
+			a XA PREPARE transaction, the server would be
+			killed, and finally, the transaction would be
+			recovered in XA PREPARE state, with some of
+			the actions already having been rolled back. */
 			trx_undo_ptr_t*	undo_ptr = &trx->rsegs.m_redo;
 			mtr_t		mtr;
 			mtr.start();
@@ -219,29 +230,15 @@ dberr_t trx_rollback_for_mysql(trx_t* trx)
 					true, &mtr);
 			}
 			mutex_exit(&trx->rsegs.m_redo.rseg->mutex);
-			/* Persist the XA ROLLBACK, so that crash
-			recovery will replay the rollback in case
-			the redo log gets applied past this point. */
+			/* Write the redo log for the XA ROLLBACK
+			state change to the global buffer. It is
+			not necessary to flush the redo log. If
+			a durable log write of a later mini-transaction
+			takes place for whatever reason, then this state
+			change will be durable as well. */
 			mtr.commit();
 			ut_ad(mtr.commit_lsn() > 0);
 		}
-#ifdef ENABLED_DEBUG_SYNC
-		if (trx->mysql_thd == NULL) {
-			/* We could be executing XA ROLLBACK after
-			XA PREPARE and a server restart. */
-		} else if (!trx->has_logged_persistent()) {
-			/* innobase_close_connection() may roll back a
-			transaction that did not generate any
-			persistent undo log. The DEBUG_SYNC
-			would cause an assertion failure for a
-			disconnected thread.
-
-			NOTE: InnoDB will not know about the XID
-			if no persistent undo log was generated. */
-		} else {
-			DEBUG_SYNC_C("trx_xa_rollback");
-		}
-#endif /* ENABLED_DEBUG_SYNC */
 		return(trx_rollback_for_mysql_low(trx));
 
 	case TRX_STATE_COMMITTED_IN_MEMORY: