Merge 10.4 into 10.5

A conflict between MDEV-19514 (b42294bc6409794bdbd2051b32fa079d81cea61d)
and MDEV-20934 (d7a2401750bb29dfdb45929a536539b9f17b347f)
was resolved. We will not invoke the function ibuf_delete_recs()
from ibuf_merge_or_delete_for_page(). Instead, we will add that
logic to the function ibuf_read_merge_pages().

27 files changed, 444 insertions, 143 deletions

diff --git a/extra/mariabackup/backup_copy.cc b/extra/mariabackup/backup_copy.cc
index 21e574ae3b8..6ede0288e3a 100644
--- a/extra/mariabackup/backup_copy.cc
+++ b/extra/mariabackup/backup_copy.cc
@@ -478,7 +478,7 @@ struct datafile_cur_t {
 	{
 		memset(rel_path, 0, sizeof rel_path);
 		if (filename) {
-			strncpy(abs_path, filename, sizeof abs_path);
+			strncpy(abs_path, filename, sizeof abs_path - 1);
 			abs_path[(sizeof abs_path) - 1] = 0;
 		} else {
 			abs_path[0] = '\0';
diff --git a/extra/mariabackup/changed_page_bitmap.cc b/extra/mariabackup/changed_page_bitmap.cc
index fcfb33c500a..5266bed800d 100644
--- a/extra/mariabackup/changed_page_bitmap.cc
+++ b/extra/mariabackup/changed_page_bitmap.cc
@@ -390,7 +390,7 @@ log_online_setup_bitmap_file_range(
 
 			bitmap_files->files[array_pos].seq_num = file_seq_num;
 			strncpy(bitmap_files->files[array_pos].name,
-				bitmap_dir_file_info.name, FN_REFLEN);
+				bitmap_dir_file_info.name, FN_REFLEN - 1);
 			bitmap_files->files[array_pos].name[FN_REFLEN - 1]
 				= '\0';
 			bitmap_files->files[array_pos].start_lsn
diff --git a/include/heap.h b/include/heap.h
index d0c907a48b4..ca6efa48f1b 100644
--- a/include/heap.h
+++ b/include/heap.h
@@ -246,7 +246,7 @@ int hp_panic(enum ha_panic_function flag);
 int heap_rkey(HP_INFO *info, uchar *record, int inx, const uchar *key,
               key_part_map keypart_map, enum ha_rkey_function find_flag);
 extern uchar * heap_find(HP_INFO *info,int inx,const uchar *key);
-extern int heap_check_heap(HP_INFO *info, my_bool print_status);
+extern int heap_check_heap(const HP_INFO *info, my_bool print_status);
 extern uchar *heap_position(HP_INFO *info);
 
 /* The following is for programs that uses the old HEAP interface where
diff --git a/mysql-test/main/join_outer_innodb.result b/mysql-test/main/join_outer_innodb.result
index ccd73ec955f..a0358094baa 100644
--- a/mysql-test/main/join_outer_innodb.result
+++ b/mysql-test/main/join_outer_innodb.result
@@ -434,46 +434,46 @@ where t1.a10 = 1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	a4,a6,a5,a7	NULL	NULL	NULL	3	Using where
 1	SIMPLE	t8	eq_ref	PRIMARY	PRIMARY	1	test.t1.a4	1	Using index
+1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	1	test.t1.a7	1	
 1	SIMPLE	t11	eq_ref	PRIMARY	PRIMARY	4	test.t1.a5	1	
 1	SIMPLE	t12	eq_ref	PRIMARY	PRIMARY	4	test.t11.k3	1	Using where
 1	SIMPLE	l2	eq_ref	PRIMARY	PRIMARY	4	test.t11.k4	1	Using where
 1	SIMPLE	t13	ref	PRIMARY,m3	PRIMARY	4	test.t1.a1	1	Using where; Using index
 1	SIMPLE	t2	ref	PRIMARY	PRIMARY	4	test.t1.a1	1	Using index
-1	SIMPLE	t9	ref	PRIMARY	PRIMARY	1	test.t1.a4	1	
 1	SIMPLE	l4	eq_ref	PRIMARY	PRIMARY	4	test.t13.m2	1	Using where; Using index
 1	SIMPLE	m2	ref	PRIMARY,m3	PRIMARY	4	test.t1.a1	1	Using where; Using index
 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.b2	1	Using where; Using index
+1	SIMPLE	t9	ref	PRIMARY	PRIMARY	1	test.t1.a4	1	
+1	SIMPLE	l3	eq_ref	PRIMARY	PRIMARY	4	test.m2.m2	1	Using where
+1	SIMPLE	t14	ALL	PRIMARY	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t4	eq_ref	PRIMARY	PRIMARY	4	test.t1.a2	1	Using index
-1	SIMPLE	t5	ALL	PRIMARY	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
-1	SIMPLE	l3	ALL	PRIMARY	NULL	NULL	NULL	3	Using where; Using join buffer (incremental, BNL join)
-1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	1	test.t1.a7	1	
-1	SIMPLE	t6	eq_ref	PRIMARY	PRIMARY	4	test.t1.a3	1	Using where; Using index
-1	SIMPLE	t14	eq_ref	PRIMARY	PRIMARY	2	test.t1.a8	1	Using where
 1	SIMPLE	t15	eq_ref	PRIMARY	PRIMARY	2	test.t1.a9	1	Using where; Using index
 1	SIMPLE	t16	ref	PRIMARY	PRIMARY	2	test.t15.o1	1	Using where
 1	SIMPLE	t10	ALL	PRIMARY	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.d1	1	Using where
+1	SIMPLE	t6	eq_ref	PRIMARY	PRIMARY	4	test.t1.a3	1	Using where; Using index
 explain select * from v1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	a4,a6,a5,a7	NULL	NULL	NULL	3	Using where
 1	SIMPLE	t8	eq_ref	PRIMARY	PRIMARY	1	test.t1.a4	1	Using index
+1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	1	test.t1.a7	1	
 1	SIMPLE	t11	eq_ref	PRIMARY	PRIMARY	4	test.t1.a5	1	
 1	SIMPLE	t12	eq_ref	PRIMARY	PRIMARY	4	test.t11.k3	1	Using where
 1	SIMPLE	l2	eq_ref	PRIMARY	PRIMARY	4	test.t11.k4	1	Using where
 1	SIMPLE	t13	ref	PRIMARY,m3	PRIMARY	4	test.t1.a1	1	Using where; Using index
 1	SIMPLE	t2	ref	PRIMARY	PRIMARY	4	test.t1.a1	1	Using index
-1	SIMPLE	t9	ref	PRIMARY	PRIMARY	1	test.t1.a4	1	
 1	SIMPLE	l4	eq_ref	PRIMARY	PRIMARY	4	test.t13.m2	1	Using where; Using index
 1	SIMPLE	m2	ref	PRIMARY,m3	PRIMARY	4	test.t1.a1	1	Using where; Using index
 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.b2	1	Using where; Using index
+1	SIMPLE	t9	ref	PRIMARY	PRIMARY	1	test.t1.a4	1	
+1	SIMPLE	l3	eq_ref	PRIMARY	PRIMARY	4	test.m2.m2	1	Using where
+1	SIMPLE	t14	ALL	PRIMARY	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t4	eq_ref	PRIMARY	PRIMARY	4	test.t1.a2	1	Using index
-1	SIMPLE	t5	ALL	PRIMARY	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
-1	SIMPLE	l3	ALL	PRIMARY	NULL	NULL	NULL	3	Using where; Using join buffer (incremental, BNL join)
-1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	1	test.t1.a7	1	
-1	SIMPLE	t6	eq_ref	PRIMARY	PRIMARY	4	test.t1.a3	1	Using where; Using index
-1	SIMPLE	t14	eq_ref	PRIMARY	PRIMARY	2	test.t1.a8	1	Using where
 1	SIMPLE	t15	eq_ref	PRIMARY	PRIMARY	2	test.t1.a9	1	Using where; Using index
 1	SIMPLE	t16	ref	PRIMARY	PRIMARY	2	test.t15.o1	1	Using where
 1	SIMPLE	t10	ALL	PRIMARY	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.d1	1	Using where
+1	SIMPLE	t6	eq_ref	PRIMARY	PRIMARY	4	test.t1.a3	1	Using where; Using index
 drop view v1;
 drop table t1,t2,t3,t4,t5,t6,t7,t8,t9,t10,t11,t12,t13,t14,t15,t16;
 #
diff --git a/mysql-test/main/selectivity.result b/mysql-test/main/selectivity.result
index f11fee4b985..c548748b242 100644
--- a/mysql-test/main/selectivity.result
+++ b/mysql-test/main/selectivity.result
@@ -1753,5 +1753,62 @@ a
 1991
 set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity;
 DROP TABLE t1;
+#
+# MDEV-20424: New default value for optimizer_use_condition-selectivity
+# leads to bad plan
+#
+create table t1(a int, b int, c int, d int, key(a,b));
+insert into t1 select 50,seq-1,seq-1,seq from seq_1_to_10;
+insert into t1 select seq-1,seq-1,seq-1,seq from seq_1_to_100 limit 90;
+create table t2(a int, b int, c int, primary key(a));
+insert into t2 select seq-1,seq-1,seq-1 from seq_1_to_100;
+create table t3(a int, b int, c int, primary key(a));
+insert into t3 select seq-1,seq-1,seq-1 from seq_1_to_100 limit 30;
+set optimizer_use_condition_selectivity=1;
+explain extended select t1.b,t2.a,t3.a,t3.b from t1,t2,t3
+where t1.c = t2.a AND t1.d = t3.a and t1.a = 50 and t1.b <= 100;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	range	a	a	10	NULL	9	100.00	Using index condition; Using where
+1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.d	1	100.00	
+1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.c	1	100.00	Using index
+Warnings:
+Note	1003	select `test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b` from `test`.`t1` join `test`.`t2` join `test`.`t3` where `test`.`t2`.`a` = `test`.`t1`.`c` and `test`.`t3`.`a` = `test`.`t1`.`d` and `test`.`t1`.`a` = 50 and `test`.`t1`.`b` <= 100
+select t1.b,t2.a,t3.a,t3.b from t1,t2,t3
+where t1.c = t2.a AND t1.d = t3.a and t1.a = 50 and t1.b <= 100;
+b	a	a	b
+0	0	1	1
+1	1	2	2
+2	2	3	3
+3	3	4	4
+4	4	5	5
+5	5	6	6
+6	6	7	7
+7	7	8	8
+8	8	9	9
+9	9	10	10
+set optimizer_use_condition_selectivity=2;
+explain extended select t1.b,t2.a,t3.a,t3.b from t1,t2,t3
+where t1.c = t2.a AND t1.d = t3.a and t1.a = 50 and t1.b <= 100;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	range	a	a	10	NULL	9	9.00	Using index condition; Using where
+1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.d	1	100.00	
+1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.c	1	100.00	Using index
+Warnings:
+Note	1003	select `test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b` from `test`.`t1` join `test`.`t2` join `test`.`t3` where `test`.`t2`.`a` = `test`.`t1`.`c` and `test`.`t3`.`a` = `test`.`t1`.`d` and `test`.`t1`.`a` = 50 and `test`.`t1`.`b` <= 100
+select t1.b,t2.a,t3.a,t3.b from t1,t2,t3
+where t1.c = t2.a AND t1.d = t3.a and t1.a = 50 and t1.b <= 100;
+b	a	a	b
+0	0	1	1
+1	1	2	2
+2	2	3	3
+3	3	4	4
+4	4	5	5
+5	5	6	6
+6	6	7	7
+7	7	8	8
+8	8	9	9
+9	9	10	10
+set optimizer_use_condition_selectivity= @@optimizer_use_condition_selectivity;
+drop table t1,t2,t3;
 # End of 10.1 tests
 set @@global.histogram_size=@save_histogram_size;
diff --git a/mysql-test/main/selectivity.test b/mysql-test/main/selectivity.test
index a9588ea205d..3cf4f320994 100644
--- a/mysql-test/main/selectivity.test
+++ b/mysql-test/main/selectivity.test
@@ -1206,6 +1206,35 @@ set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivit
 
 DROP TABLE t1;
 
+--echo #
+--echo # MDEV-20424: New default value for optimizer_use_condition-selectivity
+--echo # leads to bad plan
+--echo #
+
+create table t1(a int, b int, c int, d int, key(a,b));
+insert into t1 select 50,seq-1,seq-1,seq from seq_1_to_10;
+insert into t1 select seq-1,seq-1,seq-1,seq from seq_1_to_100 limit 90;
+
+create table t2(a int, b int, c int, primary key(a));
+insert into t2 select seq-1,seq-1,seq-1 from seq_1_to_100;
+
+create table t3(a int, b int, c int, primary key(a));
+insert into t3 select seq-1,seq-1,seq-1 from seq_1_to_100 limit 30;
+
+let $query= select t1.b,t2.a,t3.a,t3.b from t1,t2,t3
+where t1.c = t2.a AND t1.d = t3.a and t1.a = 50 and t1.b <= 100;
+
+set optimizer_use_condition_selectivity=1;
+eval explain extended $query;
+eval $query;
+
+set optimizer_use_condition_selectivity=2;
+eval explain extended $query;
+eval $query;
+set optimizer_use_condition_selectivity= @@optimizer_use_condition_selectivity;
+
+drop table t1,t2,t3;
+
 --echo # End of 10.1 tests
 
 #
diff --git a/mysql-test/main/selectivity_innodb.result b/mysql-test/main/selectivity_innodb.result
index 80295473e9b..b293f6adb5f 100644
--- a/mysql-test/main/selectivity_innodb.result
+++ b/mysql-test/main/selectivity_innodb.result
@@ -1763,6 +1763,63 @@ a
 1991
 set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity;
 DROP TABLE t1;
+#
+# MDEV-20424: New default value for optimizer_use_condition-selectivity
+# leads to bad plan
+#
+create table t1(a int, b int, c int, d int, key(a,b));
+insert into t1 select 50,seq-1,seq-1,seq from seq_1_to_10;
+insert into t1 select seq-1,seq-1,seq-1,seq from seq_1_to_100 limit 90;
+create table t2(a int, b int, c int, primary key(a));
+insert into t2 select seq-1,seq-1,seq-1 from seq_1_to_100;
+create table t3(a int, b int, c int, primary key(a));
+insert into t3 select seq-1,seq-1,seq-1 from seq_1_to_100 limit 30;
+set optimizer_use_condition_selectivity=1;
+explain extended select t1.b,t2.a,t3.a,t3.b from t1,t2,t3
+where t1.c = t2.a AND t1.d = t3.a and t1.a = 50 and t1.b <= 100;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	range	a	a	10	NULL	11	100.00	Using index condition; Using where
+1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.d	1	100.00	
+1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.c	1	100.00	Using index
+Warnings:
+Note	1003	select `test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b` from `test`.`t1` join `test`.`t2` join `test`.`t3` where `test`.`t2`.`a` = `test`.`t1`.`c` and `test`.`t3`.`a` = `test`.`t1`.`d` and `test`.`t1`.`a` = 50 and `test`.`t1`.`b` <= 100
+select t1.b,t2.a,t3.a,t3.b from t1,t2,t3
+where t1.c = t2.a AND t1.d = t3.a and t1.a = 50 and t1.b <= 100;
+b	a	a	b
+0	0	1	1
+1	1	2	2
+2	2	3	3
+3	3	4	4
+4	4	5	5
+5	5	6	6
+6	6	7	7
+7	7	8	8
+8	8	9	9
+9	9	10	10
+set optimizer_use_condition_selectivity=2;
+explain extended select t1.b,t2.a,t3.a,t3.b from t1,t2,t3
+where t1.c = t2.a AND t1.d = t3.a and t1.a = 50 and t1.b <= 100;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	range	a	a	10	NULL	11	11.00	Using index condition; Using where
+1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.d	1	100.00	
+1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.c	1	100.00	Using index
+Warnings:
+Note	1003	select `test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b` from `test`.`t1` join `test`.`t2` join `test`.`t3` where `test`.`t2`.`a` = `test`.`t1`.`c` and `test`.`t3`.`a` = `test`.`t1`.`d` and `test`.`t1`.`a` = 50 and `test`.`t1`.`b` <= 100
+select t1.b,t2.a,t3.a,t3.b from t1,t2,t3
+where t1.c = t2.a AND t1.d = t3.a and t1.a = 50 and t1.b <= 100;
+b	a	a	b
+0	0	1	1
+1	1	2	2
+2	2	3	3
+3	3	4	4
+4	4	5	5
+5	5	6	6
+6	6	7	7
+7	7	8	8
+8	8	9	9
+9	9	10	10
+set optimizer_use_condition_selectivity= @@optimizer_use_condition_selectivity;
+drop table t1,t2,t3;
 # End of 10.1 tests
 set @@global.histogram_size=@save_histogram_size;
 set optimizer_switch=@save_optimizer_switch_for_selectivity_test;
diff --git a/mysql-test/main/stat_tables.result b/mysql-test/main/stat_tables.result
index 35a21377689..3ff10cc2448 100644
--- a/mysql-test/main/stat_tables.result
+++ b/mysql-test/main/stat_tables.result
@@ -218,8 +218,8 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	supplier	eq_ref	PRIMARY,i_s_nationkey	PRIMARY	4	dbt3_s001.lineitem.l_suppkey	1	Using where
 1	SIMPLE	n2	eq_ref	PRIMARY	PRIMARY	4	dbt3_s001.supplier.s_nationkey	1	
 1	SIMPLE	orders	eq_ref	PRIMARY,i_o_orderdate,i_o_custkey	PRIMARY	4	dbt3_s001.lineitem.l_orderkey	1	Using where
-1	SIMPLE	customer	eq_ref	PRIMARY,i_c_nationkey	PRIMARY	4	dbt3_s001.orders.o_custkey	1	
-1	SIMPLE	n1	ref	PRIMARY,i_n_regionkey	i_n_regionkey	5	dbt3_s001.region.r_regionkey	5	Using where
+1	SIMPLE	customer	eq_ref	PRIMARY,i_c_nationkey	PRIMARY	4	dbt3_s001.orders.o_custkey	1	Using where
+1	SIMPLE	n1	eq_ref	PRIMARY,i_n_regionkey	PRIMARY	4	dbt3_s001.customer.c_nationkey	1	Using where
 select o_year,
 sum(case when nation = 'UNITED STATES' then volume else 0 end) /
 sum(volume) as mkt_share
diff --git a/mysql-test/suite/innodb/r/ibuf_not_empty.result b/mysql-test/suite/innodb/r/ibuf_not_empty.result
index 5147521b19f..dc852dfb8e5 100644
--- a/mysql-test/suite/innodb/r/ibuf_not_empty.result
+++ b/mysql-test/suite/innodb/r/ibuf_not_empty.result
@@ -21,6 +21,11 @@ INSERT INTO t1 SELECT 0,b,c FROM t1;
 # restart: --innodb-force-recovery=6 --innodb-change-buffer-dump
 check table t1;
 Table	Op	Msg_type	Msg_text
-test.t1	check	status	OK
+test.t1	check	Warning	InnoDB: Index 'b' contains #### entries, should be 4096.
+test.t1	check	error	Corrupt
+# restart
+SET GLOBAL innodb_purge_rseg_truncate_frequency=1;
+InnoDB		0 transactions not purged
+SET GLOBAL innodb_fast_shutdown=0;
 # restart
 DROP TABLE t1;
diff --git a/mysql-test/suite/innodb/t/ibuf_not_empty.combinations b/mysql-test/suite/innodb/t/ibuf_not_empty.combinations
new file mode 100644
index 00000000000..729380593f3
--- /dev/null
+++ b/mysql-test/suite/innodb/t/ibuf_not_empty.combinations
@@ -0,0 +1,5 @@
+[strict_crc32]
+--innodb-checksum-algorithm=strict_crc32
+
+[strict_full_crc32]
+--innodb-checksum-algorithm=strict_full_crc32
diff --git a/mysql-test/suite/innodb/t/ibuf_not_empty.test b/mysql-test/suite/innodb/t/ibuf_not_empty.test
index 470d375c661..14d8728cdf8 100644
--- a/mysql-test/suite/innodb/t/ibuf_not_empty.test
+++ b/mysql-test/suite/innodb/t/ibuf_not_empty.test
@@ -42,9 +42,44 @@ INSERT INTO t1 SELECT 0,b,c FROM t1;
 INSERT INTO t1 SELECT 0,b,c FROM t1;
 INSERT INTO t1 SELECT 0,b,c FROM t1;
 INSERT INTO t1 SELECT 0,b,c FROM t1;
+let MYSQLD_DATADIR=`select @@datadir`;
+let PAGE_SIZE=`select @@innodb_page_size`;
+
+--source include/shutdown_mysqld.inc
+
+# Corrupt the change buffer bitmap, to claim that pages are clean
+perl;
+do "$ENV{MTR_SUITE_DIR}/include/crc32.pl";
+my $file = "$ENV{MYSQLD_DATADIR}/test/t1.ibd";
+open(FILE, "+<$file") || die "Unable to open $file";
+binmode FILE;
+my $ps= $ENV{PAGE_SIZE};
+my $page;
+die "Unable to read $file" unless sysread(FILE, $page, $ps) == $ps;
+my $full_crc32 = unpack("N",substr($page,54,4)) & 0x10; # FIL_SPACE_FLAGS
+die "Unable to read $file" unless sysread(FILE, $page, $ps) == $ps;
+# Clean the change buffer bitmap.
+substr($page,38,$ps - 38 - 8) = chr(0) x ($ps - 38 - 8);
+my $polynomial = 0x82f63b78; # CRC-32C
+if ($full_crc32)
+{
+    my $ck = mycrc32(substr($page, 0, $ps-4), 0, $polynomial);
+    substr($page, $ps-4, 4) = pack("N", $ck);
+}
+else
+{
+    my $ck= pack("N",mycrc32(substr($page, 4, 22), 0, $polynomial) ^
+                 mycrc32(substr($page, 38, $ps - 38 - 8), 0, $polynomial));
+    substr($page,0,4)=$ck;
+    substr($page,$ps-8,4)=$ck;
+}
+sysseek(FILE, $ps, 0) || die "Unable to rewind $file\n";
+syswrite(FILE, $page, $ps)==$ps || die "Unable to write $file\n";
+close(FILE) || die "Unable to close $file";
+EOF
 
 --let $restart_parameters= --innodb-force-recovery=6 --innodb-change-buffer-dump
---source include/restart_mysqld.inc
+--source include/start_mysqld.inc
 
 --replace_regex /contains \d+ entries/contains #### entries/
 check table t1;
@@ -52,5 +87,13 @@ check table t1;
 --let $restart_parameters=
 --source include/restart_mysqld.inc
 
+# Ensure that the slow shutdown will not time out due to running purge.
+SET GLOBAL innodb_purge_rseg_truncate_frequency=1;
+--source include/wait_all_purged.inc
+# The change buffer merge for the injected corruption must complete
+# without exceeding the 60-second shutdown_server timeout.
+SET GLOBAL innodb_fast_shutdown=0;
+--source include/restart_mysqld.inc
+
 # Cleanup
 DROP TABLE t1;
diff --git a/mysql-test/suite/innodb_fts/r/innodb_fts_misc.result b/mysql-test/suite/innodb_fts/r/innodb_fts_misc.result
index 0bcea9165b1..91f875377e2 100644
--- a/mysql-test/suite/innodb_fts/r/innodb_fts_misc.result
+++ b/mysql-test/suite/innodb_fts/r/innodb_fts_misc.result
@@ -1,4 +1,3 @@
-drop table if exists t1;
 CREATE TABLE t1 (
 id INT UNSIGNED AUTO_INCREMENT NOT NULL PRIMARY KEY,
 a VARCHAR(200),
@@ -409,7 +408,6 @@ AGAINST ('"following database"@10' IN BOOLEAN MODE);
 id
 105
 DROP TABLE t1;
-drop table if exists t50;
 set names utf8;
 "----------Test1---------"
 create table t50 (s1 varchar(60) character set utf8 collate utf8_bin) engine = innodb;
@@ -648,9 +646,6 @@ s1
 ŁŁŁŁ
 LLLL
 ŁŁŁŁ ŁŁŁŁ
-DROP TABLE if EXISTS t2;
-Warnings:
-Note	1051	Unknown table 'test.t2'
 CREATE TABLE t2 (s1 VARCHAR(60) CHARACTER SET UTF8 COLLATE UTF8_POLISH_CI) ENGINE = InnoDB;
 CREATE FULLTEXT INDEX i ON t2 ( s1);
 INSERT INTO t2 VALUES
@@ -702,9 +697,14 @@ DROP TABLE t1;
 CREATE TABLE t1 (id INT,char_column VARCHAR(60));
 CREATE TABLE t2 (FTS_DOC_ID BIGINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY, a TEXT)ENGINE=InnoDB;
 ALTER TABLE t2 DROP a;
-SET @@autocommit=0;
 CREATE FULLTEXT INDEX i ON t1 (char_column);
 INSERT INTO t1 values (1,'aaa');
+CREATE TABLE mdev20987_1(f1 INT NOT NULL, PRIMARY KEY(f1))ENGINE=InnoDB;
+CREATE TABLE mdev20987_2(f1 INT NOT NULL, f2 CHAR(100),
+FULLTEXT(f2),
+FOREIGN KEY(f1) REFERENCES mdev20987_1(f1))ENGINE=InnoDB;
+INSERT INTO mdev20987_1 VALUES(1);
+INSERT INTO mdev20987_2 VALUES(1, 'mariadb');
 # restart
 SHOW CREATE TABLE t2;
 Table	Create Table
@@ -713,12 +713,8 @@ t2	CREATE TABLE `t2` (
   PRIMARY KEY (`FTS_DOC_ID`)
 ) ENGINE=InnoDB DEFAULT CHARSET=latin1
 DELETE FROM t1 WHERE MATCH(char_column) AGAINST ('bbb');
-SET @@autocommit=1;
-DROP TABLE t1, t2;
+DROP TABLE t1, t2, mdev20987_2, mdev20987_1;
 "----------Test28---------"
-drop table if exists `fts_test`;
-Warnings:
-Note	1051	Unknown table 'test.fts_test'
 create table `fts_test`(`a` text,fulltext key(`a`))engine=innodb;
 set session autocommit=0;
 insert into `fts_test` values ('');
@@ -908,9 +904,6 @@ id	title	body
 2	How To Use MySQL Well	After you went through a ...
 3	Optimizing MySQL	In this tutorial we will show ...
 DROP TABLE articles;
-drop table if exists t1;
-Warnings:
-Note	1051	Unknown table 'test.t1'
 create table t1 (FTS_DOC_ID bigint unsigned auto_increment not null primary key,
 title varchar(200),body text,fulltext(title,body)) engine=innodb;
 insert into t1 set body='test';
diff --git a/mysql-test/suite/innodb_fts/t/innodb_fts_misc.test b/mysql-test/suite/innodb_fts/t/innodb_fts_misc.test
index 4563d6dde77..e1f4874a1d4 100644
--- a/mysql-test/suite/innodb_fts/t/innodb_fts_misc.test
+++ b/mysql-test/suite/innodb_fts/t/innodb_fts_misc.test
@@ -7,10 +7,6 @@
 let collation=UTF8_UNICODE_CI;
 --source include/have_collation.inc
 
---disable_warnings
-drop table if exists t1;
---enable_warnings
-
 # Create FTS table
 CREATE TABLE t1 (
         id INT UNSIGNED AUTO_INCREMENT NOT NULL PRIMARY KEY,
@@ -403,10 +399,6 @@ DROP TABLE t1;
 #------------------------------------------------------------------------------
 # More FTS test from peter's testing
 #------------------------------------------------------------------------------
---disable_warnings
-drop table if exists t50;
---enable_warnings
-
 set names utf8;
 
 
@@ -608,7 +600,6 @@ CREATE FULLTEXT INDEX i ON t1 (s1);
 INSERT INTO t1 VALUES
 ('a'),('b'),('c'),('d'),('ŁŁŁŁ'),('LLLL'),(NULL),('ŁŁŁŁ ŁŁŁŁ'),('LLLLLLLL');
 SELECT * FROM t1 WHERE MATCH(s1) AGAINST ('LLLL' COLLATE UTF8_UNICODE_520_CI);
-DROP TABLE if EXISTS t2;
 CREATE TABLE t2 (s1 VARCHAR(60) CHARACTER SET UTF8 COLLATE UTF8_POLISH_CI) ENGINE = InnoDB;
 CREATE FULLTEXT INDEX i ON t2 ( s1);
 INSERT INTO t2 VALUES
@@ -672,17 +663,21 @@ DROP TABLE t1;
 CREATE TABLE t1 (id INT,char_column VARCHAR(60));
 CREATE TABLE t2 (FTS_DOC_ID BIGINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY, a TEXT)ENGINE=InnoDB;
 ALTER TABLE t2 DROP a;
-SET @@autocommit=0;
 CREATE FULLTEXT INDEX i ON t1 (char_column);
 INSERT INTO t1 values (1,'aaa');
+
+CREATE TABLE mdev20987_1(f1 INT NOT NULL, PRIMARY KEY(f1))ENGINE=InnoDB;
+CREATE TABLE mdev20987_2(f1 INT NOT NULL, f2 CHAR(100),
+                FULLTEXT(f2),
+                FOREIGN KEY(f1) REFERENCES mdev20987_1(f1))ENGINE=InnoDB;
+INSERT INTO mdev20987_1 VALUES(1);
+INSERT INTO mdev20987_2 VALUES(1, 'mariadb');
 --source include/restart_mysqld.inc
 SHOW CREATE TABLE t2;
 DELETE FROM t1 WHERE MATCH(char_column) AGAINST ('bbb');
-SET @@autocommit=1;
-DROP TABLE t1, t2;
+DROP TABLE t1, t2, mdev20987_2, mdev20987_1;
 
 --echo "----------Test28---------"
-drop table if exists `fts_test`;
 create table `fts_test`(`a` text,fulltext key(`a`))engine=innodb;
 set session autocommit=0;
 insert into `fts_test` values ('');
@@ -871,8 +866,6 @@ DROP TABLE articles;
 # Test for Bug 13940669 - 64901: INNODB: ASSERTION FAILURE IN
 # THREAD 34387022112 IN FILE REM0CMP.CC LINE 5
 
-drop table if exists t1;
-
 create table t1 (FTS_DOC_ID bigint unsigned auto_increment not null primary key,
 title varchar(200),body text,fulltext(title,body)) engine=innodb;
 
diff --git a/mysql-test/suite/perfschema/r/misc.result b/mysql-test/suite/perfschema/r/misc.result
index 4c8fdca8e68..2e4d21d625a 100644
--- a/mysql-test/suite/perfschema/r/misc.result
+++ b/mysql-test/suite/perfschema/r/misc.result
@@ -134,3 +134,19 @@ truncate performance_schema.events_statements_history	0
 select * from t1	3
 insert into t1 select RAND()*10000 from t1	6
 drop table t1;
+#
+# MDEV-17896 Assertion `pfs->get_refcount() > 0' failed
+# in release_table_share
+#
+SELECT COUNT(*)<@@performance_schema_max_table_instances FROM
+performance_schema.objects_summary_global_by_type WHERE OBJECT_TYPE='TABLE';
+COUNT(*)<@@performance_schema_max_table_instances
+1
+CREATE TABLE t0(a INT);
+SELECT * FROM t0;
+a
+DROP TEMPORARY TABLE IF EXISTS t0;
+Warnings:
+Note	1051	Unknown table 'test.t0'
+FLUSH TABLE t0;
+DROP TABLE t0;
diff --git a/mysql-test/suite/perfschema/t/misc.test b/mysql-test/suite/perfschema/t/misc.test
index c9f7dc6bfc0..80ce64f0302 100644
--- a/mysql-test/suite/perfschema/t/misc.test
+++ b/mysql-test/suite/perfschema/t/misc.test
@@ -222,3 +222,51 @@ insert into t1 select RAND()*10000 from t1;
 select sql_text, rows_examined from performance_schema.events_statements_history;
 drop table t1;
 
+--echo #
+--echo # MDEV-17896 Assertion `pfs->get_refcount() > 0' failed
+--echo # in release_table_share
+--echo #
+
+# There must be at least one available slot in PFS table_share_array for
+# this test to be meaningful. If there are no free slots we must
+# restart mysqld, it is the only way to reset PFS table_share_array
+let $query= SELECT COUNT(*)<@@performance_schema_max_table_instances FROM
+  performance_schema.objects_summary_global_by_type WHERE OBJECT_TYPE='TABLE';
+
+let $free_slots_available= `$query`;
+
+if (!$free_slots_available)
+{
+  source include/restart_mysqld.inc;
+}
+eval $query;
+
+CREATE TABLE t0(a INT);
+
+# TABLE_SHARE must be cached in the table definition cache.
+SELECT * FROM t0;
+
+# Dropping t0 using DROP TEMPORARY frees up a slot in table_share_array,
+# but the persistent table is not correctly dropped, i.e. TABLE_SHARE::m_psi
+# still points to that slot in table_share_array.
+DROP TEMPORARY TABLE IF EXISTS t0;
+
+# Try re-using each and every slot in PFS table_share_array. If bug is
+# there, we re-use t0 slot.
+# The newly created table that re-uses the t0 slot ends up
+# resetting the PFS_table_share refcount.
+let $i= `SELECT @@performance_schema_max_table_instances`;
+disable_query_log;
+while ($i)
+{
+  # Memory engine is here to reduce disk IO
+  eval CREATE TABLE t$i(a INT) ENGINE=MEMORY;
+  eval DROP TABLE t$i;
+  dec $i;
+}
+enable_query_log;
+
+# FLUSH TABLE crashes the server when PFS_table_share is found with
+# an unexpected refcount.
+FLUSH TABLE t0;
+DROP TABLE t0;
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 6b87f4a3c48..268fec84e3b 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -9831,7 +9831,10 @@ prev_record_reads(const POSITION *positions, uint idx, table_map found_ref)
           #max_nested_outer_joins=64-1) will not make it any more precise.
       */
       if (pos->records_read)
+      {
         found= COST_MULT(found, pos->records_read);
+        found*= pos->cond_selectivity;
+      }
      }
   }
   return found;
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 2917a320603..2734e5680f2 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -2425,6 +2425,13 @@ int mysql_rm_table_no_locks(THD *thd, TABLE_LIST *tables, bool if_exists,
         push_warning_printf(thd, Sql_condition::WARN_LEVEL_NOTE,
                             err, ER_THD(thd, err),
                             tbl_name.c_ptr_safe());
+
+        /*
+          Our job is done here. This statement was added to avoid executing
+          unnecessary code farther below which in some strange corner cases
+          caused the server to crash (see MDEV-17896).
+        */
+        goto log_query;
       }
       else
       {
@@ -2540,6 +2547,7 @@ int mysql_rm_table_no_locks(THD *thd, TABLE_LIST *tables, bool if_exists,
       mysql_audit_drop_table(thd, table);
     }
 
+log_query:
     if (!dont_log_query && !drop_temporary)
     {
       non_tmp_table_deleted= (if_exists ? TRUE : non_tmp_table_deleted);
diff --git a/storage/heap/_check.c b/storage/heap/_check.c
index 883e67046e7..1a640fa13da 100644
--- a/storage/heap/_check.c
+++ b/storage/heap/_check.c
@@ -18,10 +18,8 @@
 
 #include "heapdef.h"
 
-static int check_one_key(HP_KEYDEF *keydef, uint keynr, ulong records,
-			 ulong blength, my_bool print_status);
-static int check_one_rb_key(HP_INFO *info, uint keynr, ulong records,
-			    my_bool print_status);
+static int check_one_key(HP_KEYDEF *, uint, ulong, ulong, my_bool);
+static int check_one_rb_key(const HP_INFO *, uint, ulong, my_bool);
 
 
 /*
@@ -40,13 +38,13 @@ static int check_one_rb_key(HP_INFO *info, uint keynr, ulong records,
     1 error
 */
 
-int heap_check_heap(HP_INFO *info, my_bool print_status)
+int heap_check_heap(const HP_INFO *info, my_bool print_status)
 {
   int error;
   uint key;
   ulong records=0, deleted=0, pos, next_block;
   HP_SHARE *share=info->s;
-  HP_INFO save_info= *info;			/* Needed because scan_init */
+  uchar *current_ptr= info->current_ptr;
   DBUG_ENTER("heap_check_heap");
 
   for (error=key= 0 ; key < share->keys ; key++)
@@ -65,7 +63,7 @@ int heap_check_heap(HP_INFO *info, my_bool print_status)
   {
     if (pos < next_block)
     {
-      info->current_ptr+= share->block.recbuffer;
+      current_ptr+= share->block.recbuffer;
     }
     else
     {
@@ -77,9 +75,9 @@ int heap_check_heap(HP_INFO *info, my_bool print_status)
 	  break;				/* End of file */
       }
     }
-    hp_find_record(info,pos);
+    current_ptr= hp_find_block(&share->block, pos);
 
-    if (!info->current_ptr[share->visible])
+    if (!current_ptr[share->visible])
       deleted++;
     else
       records++;
@@ -92,7 +90,6 @@ int heap_check_heap(HP_INFO *info, my_bool print_status)
                         deleted, (ulong) share->deleted));
     error= 1;
   }
-  *info= save_info;
   DBUG_RETURN(error);
 }
 
@@ -165,7 +162,7 @@ static int check_one_key(HP_KEYDEF *keydef, uint keynr, ulong records,
   return error;
 }
 
-static int check_one_rb_key(HP_INFO *info, uint keynr, ulong records,
+static int check_one_rb_key(const HP_INFO *info, uint keynr, ulong records,
 			    my_bool print_status)
 {
   HP_KEYDEF *keydef= info->s->keydef + keynr;
@@ -174,9 +171,11 @@ static int check_one_rb_key(HP_INFO *info, uint keynr, ulong records,
   uchar *key, *recpos;
   uint key_length;
   uint not_used[2];
+  TREE_ELEMENT **last_pos;
+  TREE_ELEMENT *parents[MAX_TREE_HEIGHT+1];
   
-  if ((key= tree_search_edge(&keydef->rb_tree, info->parents,
-			     &info->last_pos, offsetof(TREE_ELEMENT, left))))
+  if ((key= tree_search_edge(&keydef->rb_tree, parents,
+			     &last_pos, offsetof(TREE_ELEMENT, left))))
   {
     do
     {
@@ -191,7 +190,7 @@ static int check_one_rb_key(HP_INFO *info, uint keynr, ulong records,
       }
       else
 	found++;
-      key= tree_search_next(&keydef->rb_tree, &info->last_pos,
+      key= tree_search_next(&keydef->rb_tree, &last_pos,
 			    offsetof(TREE_ELEMENT, left), 
 			    offsetof(TREE_ELEMENT, right));
     } while (key);
diff --git a/storage/innobase/dict/dict0boot.cc b/storage/innobase/dict/dict0boot.cc
index 95bd9a48edd..618f6a2ad40 100644
--- a/storage/innobase/dict/dict0boot.cc
+++ b/storage/innobase/dict/dict0boot.cc
@@ -89,8 +89,7 @@ dict_hdr_get_new_id(
 	}
 
 	if (space_id) {
-		*space_id = mtr_read_ulint(dict_hdr + DICT_HDR_MAX_SPACE_ID,
-					   MLOG_4BYTES, &mtr);
+		*space_id = mach_read_from_4(dict_hdr + DICT_HDR_MAX_SPACE_ID);
 		if (fil_assign_new_space_id(space_id)) {
 			mlog_write_ulint(dict_hdr + DICT_HDR_MAX_SPACE_ID,
 					 *space_id, MLOG_4BYTES, &mtr);
@@ -323,9 +322,9 @@ dict_boot(void)
 	dict_mem_index_add_field(index, "NAME", 0);
 
 	index->id = DICT_TABLES_ID;
-	index = dict_index_add_to_cache(
+	dberr_t error = dict_index_add_to_cache(
 		index, mach_read_from_4(dict_hdr + DICT_HDR_TABLES));
-	ut_a(index);
+	ut_a(error == DB_SUCCESS);
 	ut_ad(!table->is_instant());
 	table->indexes.start->n_core_null_bytes = UT_BITS_IN_BYTES(
 		unsigned(table->indexes.start->n_nullable));
@@ -335,9 +334,9 @@ dict_boot(void)
 	dict_mem_index_add_field(index, "ID", 0);
 
 	index->id = DICT_TABLE_IDS_ID;
-	index = dict_index_add_to_cache(
+	error = dict_index_add_to_cache(
 		index, mach_read_from_4(dict_hdr + DICT_HDR_TABLE_IDS));
-	ut_a(index);
+	ut_a(error == DB_SUCCESS);
 
 	/*-------------------------*/
 	table = dict_mem_table_create("SYS_COLUMNS", fil_system.sys_space,
@@ -365,9 +364,9 @@ dict_boot(void)
 	dict_mem_index_add_field(index, "POS", 0);
 
 	index->id = DICT_COLUMNS_ID;
-	index = dict_index_add_to_cache(
+	error = dict_index_add_to_cache(
 		index, mach_read_from_4(dict_hdr + DICT_HDR_COLUMNS));
-	ut_a(index);
+	ut_a(error == DB_SUCCESS);
 	ut_ad(!table->is_instant());
 	table->indexes.start->n_core_null_bytes = UT_BITS_IN_BYTES(
 		unsigned(table->indexes.start->n_nullable));
@@ -408,9 +407,9 @@ dict_boot(void)
 	dict_mem_index_add_field(index, "ID", 0);
 
 	index->id = DICT_INDEXES_ID;
-	index = dict_index_add_to_cache(
+	error = dict_index_add_to_cache(
 		index, mach_read_from_4(dict_hdr + DICT_HDR_INDEXES));
-	ut_a(index);
+	ut_a(error == DB_SUCCESS);
 	ut_ad(!table->is_instant());
 	table->indexes.start->n_core_null_bytes = UT_BITS_IN_BYTES(
 		unsigned(table->indexes.start->n_nullable));
@@ -437,9 +436,9 @@ dict_boot(void)
 	dict_mem_index_add_field(index, "POS", 0);
 
 	index->id = DICT_FIELDS_ID;
-	index = dict_index_add_to_cache(
+	error = dict_index_add_to_cache(
 		index, mach_read_from_4(dict_hdr + DICT_HDR_FIELDS));
-	ut_a(index);
+	ut_a(error == DB_SUCCESS);
 	ut_ad(!table->is_instant());
 	table->indexes.start->n_core_null_bytes = UT_BITS_IN_BYTES(
 		unsigned(table->indexes.start->n_nullable));
diff --git a/storage/innobase/dict/dict0crea.cc b/storage/innobase/dict/dict0crea.cc
index def439034dc..a480615f739 100644
--- a/storage/innobase/dict/dict0crea.cc
+++ b/storage/innobase/dict/dict0crea.cc
@@ -1242,9 +1242,9 @@ dict_create_index_step(
 
 	if (node->state == INDEX_ADD_TO_CACHE) {
 		ut_ad(node->index->table == node->table);
-		node->index = dict_index_add_to_cache(
+		err = dict_index_add_to_cache(
 			node->index, FIL_NULL, trx_is_strict(trx),
-			&err, node->add_v);
+			node->add_v);
 
 		ut_ad((node->index == NULL) == (err != DB_SUCCESS));
 
diff --git a/storage/innobase/dict/dict0dict.cc b/storage/innobase/dict/dict0dict.cc
index f81096989d7..7cd4bb4a401 100644
--- a/storage/innobase/dict/dict0dict.cc
+++ b/storage/innobase/dict/dict0dict.cc
@@ -1462,8 +1462,7 @@ dict_table_rename_in_cache(
 			/* The old table name in my_charset_filename is stored
 			in old_name_cs_filename */
 
-			strncpy(old_name_cs_filename, old_name,
-				MAX_FULL_NAME_LEN);
+			strcpy(old_name_cs_filename, old_name);
 			old_name_cs_filename[MAX_FULL_NAME_LEN] = '\0';
 			if (strstr(old_name, TEMP_TABLE_PATH_PREFIX) == NULL) {
 
@@ -1485,8 +1484,7 @@ dict_table_rename_in_cache(
 				} else {
 					/* Old name already in
 					my_charset_filename */
-					strncpy(old_name_cs_filename, old_name,
-						MAX_FULL_NAME_LEN);
+					strcpy(old_name_cs_filename, old_name);
 					old_name_cs_filename[MAX_FULL_NAME_LEN]
 						= '\0';
 				}
@@ -1936,23 +1934,19 @@ add_field_size:
 
 /** Adds an index to the dictionary cache, with possible indexing newly
 added column.
-@param[in]	index	index; NOTE! The index memory
+@param[in,out]	index	index; NOTE! The index memory
 			object is freed in this function!
 @param[in]	page_no	root page number of the index
-@param[in]	strict	TRUE=refuse to create the index
+@param[in]	strict	true=refuse to create the index
 			if records could be too big to fit in
 			an B-tree page
-@param[out]	err	DB_SUCCESS, DB_TOO_BIG_RECORD, or DB_CORRUPTION
-@param[in]	add_v	new virtual column that being added along with
-			an add index call
-@return	the added index
-@retval	NULL	on error */
-dict_index_t*
+@param[in]	add_v	virtual columns being added along with ADD INDEX
+@return DB_SUCCESS, DB_TOO_BIG_RECORD, or DB_CORRUPTION */
+dberr_t
 dict_index_add_to_cache(
-	dict_index_t*		index,
+	dict_index_t*&		index,
 	ulint			page_no,
 	bool			strict,
-	dberr_t*		err,
 	const dict_add_v_col_t* add_v)
 {
 	dict_index_t*	new_index;
@@ -1973,8 +1967,8 @@ dict_index_add_to_cache(
 	if (!dict_index_find_cols(index, add_v)) {
 
 		dict_mem_index_free(index);
-		if (err) *err = DB_CORRUPTION;
-		return NULL;
+		index = NULL;
+		return DB_CORRUPTION;
 	}
 
 	/* Build the cache internal representation of the index,
@@ -2006,8 +2000,8 @@ dict_index_add_to_cache(
 		if (strict) {
 			dict_mem_index_free(new_index);
 			dict_mem_index_free(index);
-			if (err) *err = DB_TOO_BIG_RECORD;
-			return NULL;
+			index = NULL;
+			return DB_TOO_BIG_RECORD;
 		} else if (current_thd != NULL) {
 			/* Avoid the warning to be printed
 			during recovery. */
@@ -2085,8 +2079,8 @@ dict_index_add_to_cache(
 	new_index->n_core_fields = new_index->n_fields;
 
 	dict_mem_index_free(index);
-	if (err) *err = DB_SUCCESS;
-	return new_index;
+	index = new_index;
+	return DB_SUCCESS;
 }
 
 /**********************************************************************//**
diff --git a/storage/innobase/dict/dict0load.cc b/storage/innobase/dict/dict0load.cc
index df4786a7e20..2cf4410b936 100644
--- a/storage/innobase/dict/dict0load.cc
+++ b/storage/innobase/dict/dict0load.cc
@@ -2566,8 +2566,9 @@ corrupted:
 			and simply did not load this index definition, the
 			.frm file would disagree with the index definitions
 			inside InnoDB. */
-			if (!dict_index_add_to_cache(
-				    index, index->page, false, &error)) {
+			if ((error = dict_index_add_to_cache(index,
+							     index->page))
+			    != DB_SUCCESS) {
 				goto func_exit;
 			}
 		}
@@ -3080,7 +3081,7 @@ func_exit:
 			fts_free(table);
 		} else if (fts_optimize_wq) {
 			fts_optimize_add_table(table);
-		} else {
+		} else if (table->can_be_evicted) {
 			/* fts_optimize_thread is not started yet.
 			So make the table as non-evictable from cache. */
 			dict_sys.prevent_eviction(table);
diff --git a/storage/innobase/handler/handler0alter.cc b/storage/innobase/handler/handler0alter.cc
index 565171529af..476de28c423 100644
--- a/storage/innobase/handler/handler0alter.cc
+++ b/storage/innobase/handler/handler0alter.cc
@@ -6559,9 +6559,8 @@ new_clustered_failed:
 		    trx_is_strict(ctx->trx))) {
 		for (uint a = 0; a < ctx->num_to_add_index; a++) {
 			ctx->add_index[a]->table = ctx->new_table;
-			ctx->add_index[a] = dict_index_add_to_cache(
-				ctx->add_index[a], FIL_NULL, false,
-				&error, add_v);
+			error = dict_index_add_to_cache(
+				ctx->add_index[a], FIL_NULL, false, add_v);
 			ut_a(error == DB_SUCCESS);
 		}
 
diff --git a/storage/innobase/ibuf/ibuf0ibuf.cc b/storage/innobase/ibuf/ibuf0ibuf.cc
index 55bcd331f27..2f12b1e9aaf 100644
--- a/storage/innobase/ibuf/ibuf0ibuf.cc
+++ b/storage/innobase/ibuf/ibuf0ibuf.cc
@@ -2372,10 +2372,26 @@ ibuf_get_merge_pages(
 	return(volume);
 }
 
+/**
+Delete a change buffer record.
+@param[in]	space		tablespace identifier
+@param[in]	page_no		page number
+@param[in,out]	pcur		persistent cursor positioned on the record
+@param[in]	search_tuple	search key for (space,page_no)
+@param[in,out]	mtr		mini-transaction
+@return whether mtr was committed (due to pessimistic operation) */
+static MY_ATTRIBUTE((warn_unused_result, nonnull))
+bool ibuf_delete_rec(ulint space, ulint page_no, btr_pcur_t* pcur,
+		     const dtuple_t* search_tuple, mtr_t* mtr);
+
 /** Merge the change buffer to some pages. */
 static void ibuf_read_merge_pages(const ulint* space_ids,
 				  const ulint* page_nos, ulint n_stored)
 {
+	mem_heap_t* heap = mem_heap_create(512);
+	ulint dops[IBUF_OP_COUNT];
+	memset(dops, 0, sizeof(dops));
+
 	for (ulint i = 0; i < n_stored; i++) {
 		const ulint space_id = space_ids[i];
 		fil_space_t* s = fil_space_acquire_for_io(space_id);
@@ -2396,14 +2412,63 @@ tablespace_deleted:
 		mtr_t mtr;
 		mtr.start();
 		dberr_t err;
-		buf_page_get_gen(page_id_t(space_id, page_nos[i]),
-				 zip_size, RW_X_LATCH, NULL, BUF_GET,
+		buf_page_get_gen(page_id_t(space_id, page_nos[i]), zip_size,
+				 RW_X_LATCH, NULL, BUF_GET,
 				 __FILE__, __LINE__, &mtr, &err, true);
 		mtr.commit();
 		if (err == DB_TABLESPACE_DELETED) {
 			goto tablespace_deleted;
 		}
+		/* Prevent an infinite loop, by removing entries from
+		the change buffer also in the case the bitmap bits were
+		wrongly clear even though buffered changes exist. */
+		const dtuple_t* tuple = ibuf_search_tuple_build(
+			space_id, page_nos[i], heap);
+loop:
+		btr_pcur_t pcur;
+		ibuf_mtr_start(&mtr);
+		btr_pcur_open(ibuf.index, tuple, PAGE_CUR_GE, BTR_MODIFY_LEAF,
+			      &pcur, &mtr);
+		if (!btr_pcur_is_on_user_rec(&pcur)) {
+			ut_ad(btr_pcur_is_after_last_in_tree(&pcur));
+			goto done;
+		}
+
+		for (;;) {
+			ut_ad(btr_pcur_is_on_user_rec(&pcur));
+
+			const rec_t* ibuf_rec = btr_pcur_get_rec(&pcur);
+			if (ibuf_rec_get_space(&mtr, ibuf_rec) != space_id
+			    || ibuf_rec_get_page_no(&mtr, ibuf_rec)
+			    != page_nos[i]) {
+				break;
+			}
+
+			dops[ibuf_rec_get_op_type(&mtr, ibuf_rec)]++;
+			/* Delete the record from ibuf */
+			if (ibuf_delete_rec(space_id, page_nos[i],
+					    &pcur, tuple, &mtr)) {
+				/* Deletion was pessimistic and mtr
+				was committed: we start from the
+				beginning again */
+				ut_ad(mtr.has_committed());
+				goto loop;
+			}
+
+			if (btr_pcur_is_after_last_on_page(&pcur)) {
+				ibuf_mtr_commit(&mtr);
+				btr_pcur_close(&pcur);
+				goto loop;
+			}
+		}
+done:
+		ibuf_mtr_commit(&mtr);
+		btr_pcur_close(&pcur);
+		mem_heap_empty(heap);
 	}
+
+	ibuf_add_ops(ibuf.n_discarded_ops, dops);
+	mem_heap_free(heap);
 }
 
 /*********************************************************************//**
@@ -4125,23 +4190,17 @@ ibuf_restore_pos(
 	return(FALSE);
 }
 
-/*********************************************************************//**
-Deletes from ibuf the record on which pcur is positioned. If we have to
-resort to a pessimistic delete, this function commits mtr and closes
-the cursor.
-@return TRUE if mtr was committed and pcur closed in this operation */
-static MY_ATTRIBUTE((warn_unused_result))
-ibool
-ibuf_delete_rec(
-/*============*/
-	ulint		space,	/*!< in: space id */
-	ulint		page_no,/*!< in: index page number that the record
-				should belong to */
-	btr_pcur_t*	pcur,	/*!< in: pcur positioned on the record to
-				delete, having latch mode BTR_MODIFY_LEAF */
-	const dtuple_t*	search_tuple,
-				/*!< in: search tuple for entries of page_no */
-	mtr_t*		mtr)	/*!< in: mtr */
+/**
+Delete a change buffer record.
+@param[in]	space		tablespace identifier
+@param[in]	page_no		page number
+@param[in,out]	pcur		persistent cursor positioned on the record
+@param[in]	search_tuple	search key for (space,page_no)
+@param[in,out]	mtr		mini-transaction
+@return whether mtr was committed (due to pessimistic operation) */
+static MY_ATTRIBUTE((warn_unused_result, nonnull))
+bool ibuf_delete_rec(ulint space, ulint page_no, btr_pcur_t* pcur,
+		     const dtuple_t* search_tuple, mtr_t* mtr)
 {
 	ibool		success;
 	page_t*		root;
@@ -4278,9 +4337,7 @@ ibuf_merge_or_delete_for_page(
 	ulint			zip_size,
 	bool			update_ibuf_bitmap)
 {
-	mem_heap_t*	heap;
 	btr_pcur_t	pcur;
-	dtuple_t*	search_tuple;
 #ifdef UNIV_IBUF_DEBUG
 	ulint		volume			= 0;
 #endif /* UNIV_IBUF_DEBUG */
@@ -4336,8 +4393,7 @@ ibuf_merge_or_delete_for_page(
 			ibuf_mtr_commit(&mtr);
 
 			if (!bitmap_bits) {
-				/* No inserts buffered for this page */
-
+				/* No changes are buffered for this page. */
 				space->release();
 				return;
 			}
@@ -4351,9 +4407,9 @@ ibuf_merge_or_delete_for_page(
 		space = NULL;
 	}
 
-	heap = mem_heap_create(512);
+	mem_heap_t* heap = mem_heap_create(512);
 
-	search_tuple = ibuf_search_tuple_build(
+	const dtuple_t* search_tuple = ibuf_search_tuple_build(
 		page_id.space(), page_id.page_no(), heap);
 
 	if (block != NULL) {
diff --git a/storage/innobase/include/dict0dict.h b/storage/innobase/include/dict0dict.h
index feb757a4666..74bdb365e26 100644
--- a/storage/innobase/include/dict0dict.h
+++ b/storage/innobase/include/dict0dict.h
@@ -973,26 +973,21 @@ dict_make_room_in_cache(
 
 /** Adds an index to the dictionary cache, with possible indexing newly
 added column.
-@param[in]	index	index; NOTE! The index memory
+@param[in,out]	index	index; NOTE! The index memory
 			object is freed in this function!
 @param[in]	page_no	root page number of the index
 @param[in]	strict	true=refuse to create the index
 			if records could be too big to fit in
 			an B-tree page
-@param[out]	err	DB_SUCCESS, DB_TOO_BIG_RECORD, or DB_CORRUPTION
-@param[in]	add_v	new virtual column that being added along with
-			an add index call
-@return	the added index
-@retval	NULL	on error */
-dict_index_t*
+@param[in]	add_v	virtual columns being added along with ADD INDEX
+@return DB_SUCCESS, DB_TOO_BIG_RECORD, or DB_CORRUPTION */
+dberr_t
 dict_index_add_to_cache(
-	dict_index_t*		index,
+	dict_index_t*&		index,
 	ulint			page_no,
 	bool			strict = false,
-	dberr_t*		err = NULL,
 	const dict_add_v_col_t* add_v = NULL)
-	MY_ATTRIBUTE((nonnull(1)));
-
+	MY_ATTRIBUTE((warn_unused_result));
 /********************************************************************//**
 Gets the number of fields in the internal representation of an index,
 including fields added by the dictionary system.
diff --git a/storage/innobase/row/row0mysql.cc b/storage/innobase/row/row0mysql.cc
index 15daeec2e6c..8573ed137d9 100644
--- a/storage/innobase/row/row0mysql.cc
+++ b/storage/innobase/row/row0mysql.cc
@@ -2557,10 +2557,10 @@ row_create_index_for_mysql(
 	} else {
 		dict_build_index_def(table, index, trx);
 
-		/* add index to dictionary cache and also free index object. */
-		index = dict_index_add_to_cache(
-			index, FIL_NULL, trx_is_strict(trx), &err);
-		if (index) {
+		err = dict_index_add_to_cache(
+			index, FIL_NULL, trx_is_strict(trx));
+		ut_ad((index == NULL) == (err != DB_SUCCESS));
+		if (UNIV_LIKELY(err == DB_SUCCESS)) {
 			ut_ad(!index->is_instant());
 			index->n_core_null_bytes = UT_BITS_IN_BYTES(
 				unsigned(index->n_nullable));
diff --git a/support-files/CMakeLists.txt b/support-files/CMakeLists.txt
index c3ff1383f86..863e72928d2 100644
--- a/support-files/CMakeLists.txt
+++ b/support-files/CMakeLists.txt
@@ -68,11 +68,12 @@ IF(UNIX)
     IF(CHECKMODULE AND SEMODULE_PACKAGE)
       FOREACH(pol mariadb)
         SET(src ${CMAKE_CURRENT_SOURCE_DIR}/policy/selinux/${pol}.te)
-        SET(tmp ${CMAKE_CURRENT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/${pol}-pp.dir/${pol}.mod)
+        SET(tmp ${CMAKE_CURRENT_BINARY_DIR}/${pol}.mod)
         SET(out ${CMAKE_CURRENT_BINARY_DIR}/${pol}.pp)
         ADD_CUSTOM_COMMAND(OUTPUT ${out}
           COMMAND ${CHECKMODULE} -M -m ${src} -o ${tmp}
           COMMAND ${SEMODULE_PACKAGE} -m ${tmp} -o ${out}
+          COMMAND ${CMAKE_COMMAND} -E remove ${tmp}
         DEPENDS ${src})
         ADD_CUSTOM_TARGET(${pol}-pp ALL DEPENDS ${out})
         INSTALL(FILES ${out} DESTINATION ${inst_location}/policy/selinux COMPONENT SupportFiles)