MDEV-20169: main.partition_innodb fails in buildbot with wrong result

The problem is that background statistics can race with statistics update
during INSERT and cause slightly inaccurate `Rows` count in table statistics
(this is deliberate to avoid excessive locking overhead). This was seen as
occasional .result difference in the test.

Mask out the unstable `Rows` column from SHOW TABLE STATUS; the value is not
related to what is being tested in this part of the test case.

Run ANALYZE TABLE before SHOW EXPLAIN to get stable row count in output.

Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

mysql-test/main/partition_innodb.result

@@ -203,6 +203,10 @@ INSERT INTO t1 VALUES (100);
 ERROR HY000: Table has no partition for value 100
 insert INTO t1 VALUES (110);
 ERROR HY000: Table has no partition for value 110
+ANALYZE TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	analyze	status	Engine-independent statistics collected
+test.t1	analyze	status	OK
 EXPLAIN PARTITIONS SELECT * FROM t1 WHERE a > 90;
 id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
@@ -406,7 +410,7 @@ t1	InnoDB	10	Dynamic	2	8192	16384	0	0	0	NULL	Create_time	NULL	NULL	latin1_swedis
 insert into t1 values (0), (1), (2), (3);
 show table status;
 Name	Engine	Version	Row_format	Rows	Avg_row_length	Data_length	Max_data_length	Index_length	Data_free	Auto_increment	Create_time	Update_time	Check_time	Collation	Checksum	Create_options	Comment	Max_index_length	Temporary
-t1	InnoDB	10	Dynamic	4	4096	16384	0	0	0	NULL	Create_time	Update_time	NULL	latin1_swedish_ci	NULL	partitioned		0	N
+t1	InnoDB	10	Dynamic	Rows	Avg_row_length	16384	0	0	0	NULL	Create_time	Update_time	NULL	latin1_swedish_ci	NULL	partitioned		0	N
 drop table t1;
 create table t1 (a int auto_increment primary key)
 engine = innodb
@@ -417,11 +421,11 @@ t1	InnoDB	10	Dynamic	2	8192	16384	0	0	0	1	Create_time	NULL	NULL	latin1_swedish_c
 insert into t1 values (NULL), (NULL), (NULL), (NULL);
 show table status;
 Name	Engine	Version	Row_format	Rows	Avg_row_length	Data_length	Max_data_length	Index_length	Data_free	Auto_increment	Create_time	Update_time	Check_time	Collation	Checksum	Create_options	Comment	Max_index_length	Temporary
-t1	InnoDB	10	Dynamic	4	4096	16384	0	0	0	5	Create_time	Update_time	NULL	latin1_swedish_ci	NULL	partitioned		0	N
+t1	InnoDB	10	Dynamic	Rows	Avg_row_length	16384	0	0	0	5	Create_time	Update_time	NULL	latin1_swedish_ci	NULL	partitioned		0	N
 insert into t1 values (NULL), (NULL), (NULL), (NULL);
 show table status;
 Name	Engine	Version	Row_format	Rows	Avg_row_length	Data_length	Max_data_length	Index_length	Data_free	Auto_increment	Create_time	Update_time	Check_time	Collation	Checksum	Create_options	Comment	Max_index_length	Temporary
-t1	InnoDB	10	Dynamic	8	2048	16384	0	0	0	9	Create_time	Update_time	NULL	latin1_swedish_ci	NULL	partitioned		0	N
+t1	InnoDB	10	Dynamic	Rows	Avg_row_length	16384	0	0	0	9	Create_time	Update_time	NULL	latin1_swedish_ci	NULL	partitioned		0	N
 drop table t1;
 create table t1 (a int)
 partition by key (a)

mysql-test/main/partition_innodb.test

@@ -214,6 +214,7 @@ INSERT INTO t1 VALUES (90);
 INSERT INTO t1 VALUES (100);
 --error ER_NO_PARTITION_FOR_GIVEN_VALUE
 insert INTO t1 VALUES (110);
+ANALYZE TABLE t1;
 EXPLAIN PARTITIONS SELECT * FROM t1 WHERE a > 90;
 EXPLAIN PARTITIONS SELECT * FROM t1 WHERE a >= 90;
 EXPLAIN PARTITIONS SELECT * FROM t1 WHERE a = 90;
@@ -426,7 +427,9 @@ partition by key (a);
 --replace_column 12 Create_time
 show table status;
 insert into t1 values (0), (1), (2), (3);
---replace_column 12 Create_time 13 Update_time
+# Mask `Rows`, as it can fluctuate slightly if background statistics are
+# running simultaneously with insert (MDEV-20169).
+--replace_column 5 Rows 6 Avg_row_length 12 Create_time 13 Update_time
 show table status;
 drop table t1;
 
@@ -436,10 +439,10 @@ partition by key (a);
 --replace_column 12 Create_time
 show table status;
 insert into t1 values (NULL), (NULL), (NULL), (NULL);
---replace_column 12 Create_time 13 Update_time
+--replace_column 5 Rows 6 Avg_row_length 12 Create_time 13 Update_time
 show table status;
 insert into t1 values (NULL), (NULL), (NULL), (NULL);
---replace_column 12 Create_time 13 Update_time
+--replace_column 5 Rows 6 Avg_row_length 12 Create_time 13 Update_time
 show table status;
 drop table t1;