MDEV-23805 Make Online DDL to Instant DDL when table is emptybb-10.4-MDEV-23805

- In ha_innobase::prepare_inplace_alter_table(), InnoDB should
check whether the table is empty. If the table is empty then
server should avoid downgrading the MDL after prepare phase.
It is more like instant alter, does change only in dicationary
and metadata.

- Changed few debug test case to make non-empty DDL table

8 files changed, 11 insertions, 3 deletions

diff --git a/mysql-test/suite/innodb/t/alter_candidate_key.test b/mysql-test/suite/innodb/t/alter_candidate_key.test
index 7429cd89a1a..7c8f5e30993 100644
--- a/mysql-test/suite/innodb/t/alter_candidate_key.test
+++ b/mysql-test/suite/innodb/t/alter_candidate_key.test
@@ -24,6 +24,7 @@ CREATE TABLE t1(f1 INT, f2 INT,
 		PRIMARY KEY(f1, f2),
 		UNIQUE INDEX uidx2 (f1, f2),
 		UNIQUE INDEX uidx1 (f2))ENGINE=InnoDB;
+INSERT INTO t1 VALUES(2, 2);
 ALTER TABLE t1 DROP PRIMARY KEY;
 SHOW CREATE TABLE t1;
 SET DEBUG_SYNC = 'innodb_inplace_alter_table_enter
@@ -42,6 +43,7 @@ DROP TABLE t1;
 
 SET SQL_MODE= strict_trans_tables;
 CREATE TABLE t1(a INT UNIQUE) ENGINE=InnoDB;
+INSERT INTO t1 VALUES(1);
 SET DEBUG_SYNC='row_log_table_apply1_before SIGNAL dml WAIT_FOR dml_done';
 --send ALTER TABLE t1 MODIFY COLUMN a INT NOT NULL
 connection con1;
diff --git a/mysql-test/suite/innodb/t/alter_not_null_debug.test b/mysql-test/suite/innodb/t/alter_not_null_debug.test
index 7a965fd413a..9c5ba0faff0 100644
--- a/mysql-test/suite/innodb/t/alter_not_null_debug.test
+++ b/mysql-test/suite/innodb/t/alter_not_null_debug.test
@@ -75,7 +75,7 @@ SET DEBUG_SYNC='RESET';
 --echo #
 CREATE TABLE t1 (f VARCHAR(8) CHARACTER SET latin1 COLLATE latin1_swedish_ci)
 ENGINE=InnoDB;
-
+INSERT INTO t1 VALUES('ZERO');
 connection con1;
 SET DEBUG_SYNC = 'row_log_table_apply1_before SIGNAL scanned WAIT_FOR insert_done';
 send ALTER TABLE t1 MODIFY f VARCHAR(256) COLLATE latin1_german2_ci NOT NULL;
diff --git a/mysql-test/suite/innodb/t/alter_primary_key.test b/mysql-test/suite/innodb/t/alter_primary_key.test
index 4edc0cc023e..bf961c14b43 100644
--- a/mysql-test/suite/innodb/t/alter_primary_key.test
+++ b/mysql-test/suite/innodb/t/alter_primary_key.test
@@ -9,6 +9,7 @@
 
 CREATE TABLE t0 (pk INT PRIMARY KEY) ENGINE=InnoDB;
 CREATE TABLE t1 (c CHAR(2) NOT NULL) ENGINE=InnoDB;
+INSERT INTO  t1 VALUES('cd');
 
 connect (con1,localhost,root,,);
 BEGIN;
diff --git a/mysql-test/suite/innodb/t/ddl_purge.test b/mysql-test/suite/innodb/t/ddl_purge.test
index 60d17acead8..e38b68c7bc9 100644
--- a/mysql-test/suite/innodb/t/ddl_purge.test
+++ b/mysql-test/suite/innodb/t/ddl_purge.test
@@ -4,6 +4,7 @@
 
 CREATE TABLE t0 (pk INT PRIMARY KEY) ENGINE=InnoDB;
 CREATE TABLE t1 (pk INT PRIMARY KEY, b INT) ENGINE=InnoDB;
+INSERT INTO t1 VALUES(100, 100);
 
 --connect (con1,localhost,root,,test)
 BEGIN;
diff --git a/mysql-test/suite/innodb/t/innodb-alter-tempfile.test b/mysql-test/suite/innodb/t/innodb-alter-tempfile.test
index cbf8ff9e87f..dac176f3b77 100644
--- a/mysql-test/suite/innodb/t/innodb-alter-tempfile.test
+++ b/mysql-test/suite/innodb/t/innodb-alter-tempfile.test
@@ -80,7 +80,7 @@ BEGIN;
 DELETE FROM mysql.innodb_table_stats;
 
 connect (con2,localhost,root,,);
-SET DEBUG_SYNC='inplace_after_index_build SIGNAL blocked WAIT_FOR ever';
+SET DEBUG_SYNC='innodb_inplace_alter_table_enter SIGNAL blocked WAIT_FOR ever';
 send ALTER TABLE t1 FORCE;
 
 connection default;
diff --git a/mysql-test/suite/innodb/t/innodb-index-debug.test b/mysql-test/suite/innodb/t/innodb-index-debug.test
index 2988a89c651..6e31200570b 100644
--- a/mysql-test/suite/innodb/t/innodb-index-debug.test
+++ b/mysql-test/suite/innodb/t/innodb-index-debug.test
@@ -96,6 +96,7 @@ drop table t1;
 # Log file creation failure.
 create table t1(k1 int auto_increment primary key,
 k2 char(200),k3 char(200))engine=innodb;
+INSERT INTO t1 VALUES(1, "test", "test");
 SET DEBUG_SYNC= 'row_merge_after_scan
 SIGNAL opened WAIT_FOR flushed';
 send ALTER TABLE t1 FORCE, ADD COLUMN k4 int;
@@ -122,6 +123,7 @@ drop table t480;
 --echo #
 
 CREATE TABLE t1 (j INT UNIQUE, i INT UNIQUE) ENGINE=InnoDB;
+INSERT INTO t1 VALUES(2, 2);
 --connect (con1,localhost,root,,test)
 SET DEBUG_SYNC='row_log_table_apply1_before SIGNAL built WAIT_FOR log';
 --send
diff --git a/mysql-test/suite/innodb/t/innodb-index-online.test b/mysql-test/suite/innodb/t/innodb-index-online.test
index 5e21fa896a4..781ff8ee681 100644
--- a/mysql-test/suite/innodb/t/innodb-index-online.test
+++ b/mysql-test/suite/innodb/t/innodb-index-online.test
@@ -477,6 +477,7 @@ DROP TABLE t1;
 --echo # MDEV-13205 assertion !dict_index_is_online_ddl(index) upon ALTER TABLE
 --echo #
 CREATE TABLE t1 (c VARCHAR(64)) ENGINE=InnoDB;
+INSERT INTO t1 VALUES('foo');
 SET DEBUG_SYNC = 'row_log_apply_before SIGNAL t1u_created WAIT_FOR dup_done';
 send ALTER TABLE t1 ADD UNIQUE(c);
 
diff --git a/mysql-test/suite/innodb/t/instant_alter_debug.test b/mysql-test/suite/innodb/t/instant_alter_debug.test
index 10f7546cc36..8cf2610bbfb 100644
--- a/mysql-test/suite/innodb/t/instant_alter_debug.test
+++ b/mysql-test/suite/innodb/t/instant_alter_debug.test
@@ -186,6 +186,7 @@ connect stop_purge,localhost,root;
 START TRANSACTION WITH CONSISTENT SNAPSHOT;
 connect ddl,localhost,root,,test;
 DELETE FROM t1;
+INSERT INTO t1 VALUES(1, 2);
 SET DEBUG_SYNC='row_log_table_apply1_before SIGNAL copied WAIT_FOR logged';
 send ALTER TABLE t1 FORCE;
 connection default;
@@ -519,7 +520,7 @@ DROP TABLE t1;
 CREATE TABLE t1
 (a INT NOT NULL, b INT, c INT, d INT, e INT, f INT, g INT, h INT, i TEXT)
 ENGINE=InnoDB;
-
+INSERT INTO t1 VALUES(1, 2, 3, 4, 5, 6, 7, 8, "test");
 ALTER TABLE t1 MODIFY a INT NULL;
 
 SET DEBUG_SYNC='innodb_inplace_alter_table_enter SIGNAL alter WAIT_FOR go';