MDEV-21217 innodb_force_recovery=2 may wrongly abort rollback

trx_roll_must_shutdown(): Correct the condition that detects
the start of shutdown.

mysql-test/suite/innodb/r/innodb_force_recovery_rollback.result

+FLUSH TABLES;
+#
+# MDEV-21217 innodb_force_recovery=2 may wrongly abort the rollback
+# of recovered transactions
+#
+connect  con0,localhost,root;
+CREATE TABLE t0 (a INT PRIMARY KEY) ENGINE=InnoDB;
+BEGIN;
+INSERT INTO t0 SELECT * FROM seq_1_to_1000;
+connection default;
+SET GLOBAL innodb_flush_log_at_trx_commit=1;
+CREATE TABLE t1 (a INT PRIMARY KEY) ENGINE=InnoDB;
+disconnect con0;
+connection default;
+SELECT * FROM t0 LOCK IN SHARE MODE;
+a
+DROP TABLE t0,t1;

mysql-test/suite/innodb/t/innodb_force_recovery_rollback.test

+--source include/have_innodb.inc
+--source include/have_sequence.inc
+
+# We will kill and restart the server.
+--source include/not_embedded.inc
+FLUSH TABLES;
+
+--echo #
+--echo # MDEV-21217 innodb_force_recovery=2 may wrongly abort the rollback
+--echo # of recovered transactions
+--echo #
+
+connect (con0,localhost,root);
+CREATE TABLE t0 (a INT PRIMARY KEY) ENGINE=InnoDB;
+# Create enough undo log so that the rollback may take enough time.
+BEGIN;
+INSERT INTO t0 SELECT * FROM seq_1_to_1000;
+
+connection default;
+# Persist the above incomplete transaction.
+SET GLOBAL innodb_flush_log_at_trx_commit=1;
+CREATE TABLE t1 (a INT PRIMARY KEY) ENGINE=InnoDB;
+
+--let $restart_parameters= --innodb-force-recovery=2
+--let $shutdown_timeout=0
+--source include/restart_mysqld.inc
+--let $restart_parameters=
+--let $shutdown_timeout=
+
+disconnect con0;
+connection default;
+# If the rollback was aborted, we would end up in a lock wait here.
+SELECT * FROM t0 LOCK IN SHARE MODE;
+DROP TABLE t0,t1;

storage/innobase/trx/trx0roll.cc

@@ -750,7 +750,7 @@ trx_roll_must_shutdown()
 	ut_ad(trx_state_eq(trx, TRX_STATE_ACTIVE));
 
 	if (trx_get_dict_operation(trx) == TRX_DICT_OP_NONE
-	    && !srv_is_being_started
+	    && srv_shutdown_state != SRV_SHUTDOWN_NONE
 	    && !srv_undo_sources && srv_fast_shutdown) {
 		return true;
 	}