MDEV-14081 ALTER TABLE CHANGE COLUMN Corrupts Index Leading to Crashes in 10.2

remove remnants of 10.0 bugfix, incorrectly merged into 10.2

Using col_names[i] was obviously, wrong, must've been col_names[ifield->col_no].
incorrect column name resulted in innodb having index unique_id2(id1),
while the server thought it's unique_id2(id4).
But col_names[ifield->col_no] is wrong too, because `table` has non-renamed
columns, so the correct column name is always dict_table_get_col_name(table, ifield->col_no)

Author: vuvova

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

@@ -11,3 +11,14 @@ t1	CREATE TABLE `t1` (
 ) ENGINE=InnoDB DEFAULT CHARSET=latin1 ROW_FORMAT=DYNAMIC
 drop table t1;
 set @@sql_mode=default;
+create table t1 (
+id1    int(11)      not null auto_increment,
+id2    varchar(30)  not null,
+id3    datetime     not null default current_timestamp,
+primary key (id1),
+unique key unique_id2 (id2)
+) engine=innodb;
+alter table t1 change column id2 id4 varchar(100) not null;
+select * from t1 where id4 like 'a';
+id1	id4	id3
+drop table t1;

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

@@ -640,10 +640,8 @@ CHANGE foo_id FTS_DOC_ID BIGINT UNSIGNED NOT NULL;
 ALTER TABLE t1o DROP INDEX ct, DROP INDEX FTS_DOC_ID_INDEX,
 CHANGE FTS_DOC_ID foo_id BIGINT UNSIGNED NOT NULL;
 ALTER TABLE t1o ADD UNIQUE INDEX FTS_DOC_ID_INDEX(foo_id);
-call mtr.add_suppression("InnoDB: No matching column for `FTS_DOC_ID` in index `ct` of table `test`\\.`t1o`");
 ALTER TABLE t1o CHANGE foo_id FTS_DOC_ID BIGINT UNSIGNED NOT NULL,
 ADD FULLTEXT INDEX(ct);
-ERROR HY000: Index for table 't1o' is corrupt; try to repair it
 DROP TABLE sys_indexes;
 CREATE TABLE sys_indexes SELECT i.* FROM INFORMATION_SCHEMA.INNODB_SYS_INDEXES i
 INNER JOIN sys_tables st ON i.TABLE_ID=st.TABLE_ID;

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

@@ -8,3 +8,17 @@ create index idx1 on t1(a(3073));
 show create table t1;
 drop table t1;
 set @@sql_mode=default;
+
+#
+# MDEV-14081 ALTER TABLE CHANGE COLUMN Corrupts Index Leading to Crashes in 10.2
+#
+create table t1 (
+  id1    int(11)      not null auto_increment,
+  id2    varchar(30)  not null,
+  id3    datetime     not null default current_timestamp,
+  primary key (id1),
+  unique key unique_id2 (id2)
+) engine=innodb;
+alter table t1 change column id2 id4 varchar(100) not null;
+select * from t1 where id4 like 'a';
+drop table t1;

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

@@ -370,16 +370,8 @@ CHANGE FTS_DOC_ID foo_id BIGINT UNSIGNED NOT NULL;
 
 ALTER TABLE t1o ADD UNIQUE INDEX FTS_DOC_ID_INDEX(foo_id);
 
-# FIXME: MDEV-9469 'Incorrect key file' on ALTER TABLE
-call mtr.add_suppression("InnoDB: No matching column for `FTS_DOC_ID` in index `ct` of table `test`\\.`t1o`");
---error ER_NOT_KEYFILE
 ALTER TABLE t1o CHANGE foo_id FTS_DOC_ID BIGINT UNSIGNED NOT NULL,
 ADD FULLTEXT INDEX(ct);
-# FIXME: MDEV-9469 (enable this)
-#--error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
-#ALTER TABLE t1o CHANGE FTS_DOC_ID foo_id BIGINT UNSIGNED NOT NULL,
-#ALGORITHM=INPLACE;
-#end of MDEV-9469 FIXME
 
 DROP TABLE sys_indexes;
 CREATE TABLE sys_indexes SELECT i.* FROM INFORMATION_SCHEMA.INNODB_SYS_INDEXES i

storage/innobase/handler/handler0alter.cc

@@ -4850,7 +4850,7 @@ prepare_inplace_alter_table_dict(
 
 		ctx->add_index[a] = row_merge_create_index(
 			ctx->trx, ctx->new_table,
-			&index_defs[a], add_v, ctx->col_names);
+			&index_defs[a], add_v);
 
 		add_key_nums[a] = index_defs[a].key_number;
 

storage/innobase/include/row0merge.h

@@ -265,16 +265,13 @@ row_merge_rename_index_to_drop(
 @param[in]	index_def	the index definition
 @param[in]	add_v		new virtual columns added along with add
 				index call
-@param[in]	col_names	column names if columns are renamed
-				or NULL
 @return index, or NULL on error */
 dict_index_t*
 row_merge_create_index(
 	trx_t*			trx,
 	dict_table_t*		table,
 	const index_def_t*	index_def,
-	const dict_add_v_col_t*	add_v,
-	const char**		col_names)
+	const dict_add_v_col_t*	add_v)
 	MY_ATTRIBUTE((warn_unused_result));
 
 /*********************************************************************//**

storage/innobase/row/row0merge.cc

@@ -4362,16 +4362,13 @@ row_merge_create_index_graph(
 @param[in]	index_def	the index definition
 @param[in]	add_v		new virtual columns added along with add
 				index call
-@param[in]	col_names	column names if columns are renamed
-				or NULL
 @return index, or NULL on error */
 dict_index_t*
 row_merge_create_index(
 	trx_t*			trx,
 	dict_table_t*		table,
 	const index_def_t*	index_def,
-	const dict_add_v_col_t*	add_v,
-	const char**		col_names)
+	const dict_add_v_col_t*	add_v)
 {
 	dict_index_t*	index;
 	dberr_t		err;
@@ -4411,20 +4408,7 @@ row_merge_create_index(
 					table, ifield->col_no);
 			}
 		} else {
-			/*
-			Alter table renaming a column and then adding a index
-			to this new name e.g ALTER TABLE t
-			CHANGE COLUMN b c INT NOT NULL, ADD UNIQUE INDEX (c);
-			requires additional check as column names are not yet
-			changed when new index definitions are created. Table's
-			new column names are on a array of column name pointers
-			if any of the column names are changed. */
-
-			if (col_names && col_names[i]) {
-				name = col_names[i];
-			} else {
-				name = dict_table_get_col_name(table, ifield->col_no);
-			}
+			name = dict_table_get_col_name(table, ifield->col_no);
 		}
 
 		dict_mem_index_add_field(index, name, ifield->prefix_len);