diff --git a/libmariadb b/libmariadb
index c2b322d2ca2..5af90f00ffe 160000
--- a/libmariadb
+++ b/libmariadb
@@ -1 +1 @@
-Subproject commit c2b322d2ca27ef66385d9938b98541c7cf14ac74
+Subproject commit 5af90f00ffeda64795e23753c14d601cce5d02ca
diff --git a/mysql-test/main/group_min_max_notembedded.result b/mysql-test/main/group_min_max_notembedded.result
index b1606886c97..e19560b4923 100644
--- a/mysql-test/main/group_min_max_notembedded.result
+++ b/mysql-test/main/group_min_max_notembedded.result
@@ -15,10 +15,12 @@ a	b
 2	2
 select 
 CAST(json_value(json_extract(trace, '$**.chosen_access_method.cost'), '$[0]')
-as DOUBLE) < 1.0e100
+as DOUBLE) < 1.0e100  as ACCESS_METHOD_COST_IS_FINITE
 from information_schema.optimizer_trace;
-CAST(json_value(json_extract(trace, '$**.chosen_access_method.cost'), '$[0]')
-as DOUBLE) < 1.0e100
+ACCESS_METHOD_COST_IS_FINITE
 1
 set optimizer_use_condition_selectivity = @tmp, optimizer_trace=@tmp2;
 drop table t1;
+#
+# End of 10.5 tests
+#
diff --git a/mysql-test/main/group_min_max_notembedded.test b/mysql-test/main/group_min_max_notembedded.test
index 9da7e9f54b0..930ee8464f8 100644
--- a/mysql-test/main/group_min_max_notembedded.test
+++ b/mysql-test/main/group_min_max_notembedded.test
@@ -1,7 +1,10 @@
---source include/no_valgrind_without_big.inc
+#
+# Tests for group-min-max optimization that require optimizer trace
+# and so need not-embedded.
+#
 --source include/default_optimizer_switch.inc
---source include/have_sequence.inc
 --source include/have_innodb.inc
+--source include/have_sequence.inc
 --source include/not_embedded.inc
 
 --echo # 
@@ -22,8 +25,13 @@ SELECT DISTINCT * FROM t1 WHERE a IN (1, 2);
 
 select 
   CAST(json_value(json_extract(trace, '$**.chosen_access_method.cost'), '$[0]')
-       as DOUBLE) < 1.0e100
+       as DOUBLE) < 1.0e100  as ACCESS_METHOD_COST_IS_FINITE
 from information_schema.optimizer_trace;
 
 set optimizer_use_condition_selectivity = @tmp, optimizer_trace=@tmp2;
 drop table t1;
+
+--echo #
+--echo # End of 10.5 tests
+--echo #
+
diff --git a/mysql-test/main/join.result b/mysql-test/main/join.result
index 942ee96fc32..427b06aabbe 100644
--- a/mysql-test/main/join.result
+++ b/mysql-test/main/join.result
@@ -3424,3 +3424,18 @@ COUNT(*)
 2
 DROP TABLE t1, t2, t3;
 # End of 10.5 tests
+#
+# MDEV-31449: Assertion s->table->opt_range_condition_rows <= s->found_records
+#
+CREATE TABLE t1 (a INT, b INT);
+INSERT INTO t1 VALUES (1,2),(3,4);
+CREATE TABLE t2 (c INT);
+INSERT INTO t2 VALUES (5),(6);
+SET @tmp=@@OPTIMIZER_USE_CONDITION_SELECTIVITY, OPTIMIZER_USE_CONDITION_SELECTIVITY = 1;
+SELECT * FROM
+(SELECT t1.* FROM t1 WHERE t1.a IN (SELECT MAX(t2.c) FROM t2 JOIN t1)) AS sq1,
+(SELECT t2.* FROM t2 JOIN t1 ON (t1.b IN (SELECT t1.b FROM t2 STRAIGHT_JOIN t1))) AS sq2;
+a	b	c
+SET OPTIMIZER_USE_CONDITION_SELECTIVITY=@tmp;
+DROP TABLE t1,t2;
+# End of 10.6 tests
diff --git a/mysql-test/main/join.test b/mysql-test/main/join.test
index c8bd2886b30..b665f034813 100644
--- a/mysql-test/main/join.test
+++ b/mysql-test/main/join.test
@@ -1835,3 +1835,22 @@ SELECT COUNT(*) FROM t1 LEFT JOIN (t2 LEFT JOIN t3 ON t2.b = t3.c) ON t1.a = t2.
 DROP TABLE t1, t2, t3;
 
 --echo # End of 10.5 tests
+
+--echo #
+--echo # MDEV-31449: Assertion s->table->opt_range_condition_rows <= s->found_records
+--echo #
+CREATE TABLE t1 (a INT, b INT);
+INSERT INTO t1 VALUES (1,2),(3,4);
+
+CREATE TABLE t2 (c INT);
+INSERT INTO t2 VALUES (5),(6);
+
+SET @tmp=@@OPTIMIZER_USE_CONDITION_SELECTIVITY, OPTIMIZER_USE_CONDITION_SELECTIVITY = 1;
+
+SELECT * FROM
+(SELECT t1.* FROM t1 WHERE t1.a IN (SELECT MAX(t2.c) FROM t2 JOIN t1)) AS sq1,
+(SELECT t2.* FROM t2 JOIN t1 ON (t1.b IN (SELECT t1.b FROM t2 STRAIGHT_JOIN t1))) AS sq2;
+
+SET OPTIMIZER_USE_CONDITION_SELECTIVITY=@tmp;
+DROP TABLE t1,t2;
+--echo # End of 10.6 tests
diff --git a/sql/multi_range_read.cc b/sql/multi_range_read.cc
index 2701dac56c4..2180cbb66b2 100644
--- a/sql/multi_range_read.cc
+++ b/sql/multi_range_read.cc
@@ -2008,6 +2008,9 @@ bool DsMrr_impl::get_disk_sweep_mrr_cost(uint keynr, ha_rows rows, uint flags,
   /* Total cost of all index accesses */
   index_read_cost= primary_file->keyread_time(keynr, 1, rows);
   cost->add_io(index_read_cost, 1 /* Random seeks */);
+
+  cost->cpu_cost+= (rows2double(rows) / TIME_FOR_COMPARE +
+                   MULTI_RANGE_READ_SETUP_COST);
   return FALSE;
 }
 
diff --git a/sql/sql_priv.h b/sql/sql_priv.h
index 76260ec51e7..549f279e95a 100644
--- a/sql/sql_priv.h
+++ b/sql/sql_priv.h
@@ -190,7 +190,7 @@
 /* The rest of the file is included in the server only */
 #ifndef MYSQL_CLIENT
 
-/* @@optimizer_switch flags. These must be in sync with optimizer_switch_typelib */
+/* @@optimizer_switch flags. These must be in sync with optimizer_switch_names */
 #define OPTIMIZER_SWITCH_INDEX_MERGE               (1ULL << 0)
 #define OPTIMIZER_SWITCH_INDEX_MERGE_UNION         (1ULL << 1)
 #define OPTIMIZER_SWITCH_INDEX_MERGE_SORT_UNION    (1ULL << 2)
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 709a456cd9b..f9b655d5af7 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -5799,7 +5799,7 @@ make_join_statistics(JOIN *join, List<TABLE_LIST> &tables_list,
         get_delayed_table_estimates(s->table, &s->records, &s->read_time,
                                     &s->startup_cost);
         s->found_records= s->records;
-        table->opt_range_condition_rows=s->records;
+        s->table->opt_range_condition_rows=s->records;
       }
       else
         s->scan_time();
diff --git a/storage/innobase/include/fil0fil.h b/storage/innobase/include/fil0fil.h
index 3d88e6ad48f..c3aadd587e0 100644
--- a/storage/innobase/include/fil0fil.h
+++ b/storage/innobase/include/fil0fil.h
@@ -1655,9 +1655,11 @@ template<bool have_reference> inline void fil_space_t::flush()
     flush_low();
   else
   {
-    if (!(acquire_low() & (STOPPING | CLOSING)))
+    if (!(acquire_low(STOPPING | CLOSING) & (STOPPING | CLOSING)))
+    {
       flush_low();
-    release();
+      release();
+    }
   }
 }