MDEV-21478 Inplace ALTER fails to report error when FTS_DOC_ID

		with wrong data type is added

  Inplace alter fails to report error when fts_doc_id column with
wrong data type is added.

prepare_inplace_alter_table_dict(): Should check whether the column
is fts_doc_id. It should be of bigint type, should accept non null
data type and it should be in capital letters.

mysql-test/suite/innodb_fts/r/innodb-fts-ddl.result

@@ -234,3 +234,35 @@ CREATE TABLE t1 (FTS_DOC_ID BIGINT UNSIGNED PRIMARY KEY,
 f1 VARCHAR(200),FULLTEXT fidx(f1))engine=innodb;
 ALTER TABLE t1 DROP index fidx, ADD FULLTEXT INDEX(f1);
 DROP TABLE t1;
+#
+# MDEV-21478 Inplace alter fails to report error when
+#	FTS_DOC_ID is added
+SET NAMES utf8;
+CREATE TABLE t1(f1 INT NOT NULL)ENGINE=InnoDB;
+ALTER TABLE t1 ADD FTS_DOC_ıD BIGINT UNSIGNED NOT NULL, ALGORITHM=COPY;
+ALTER TABLE t1 DROP COLUMN FTS_DOC_ıD;
+ALTER TABLE t1 ADD FTS_DOC_ıD BIGINT UNSIGNED NOT NULL, ALGORITHM=INPLACE;
+DROP TABLE t1;
+CREATE TABLE t1 (f1 INT NOT NULL)ENGINE=InnoDB;
+ALTER TABLE t1 ADD FTS_DOC_İD BIGINT UNSIGNED NOT NULL, ALGORITHM=INPLACE;
+ERROR 42000: Incorrect column name 'FTS_DOC_İD'
+ALTER TABLE t1 ADD FTS_DOC_İD BIGINT UNSIGNED NOT NULL, ALGORITHM=COPY;
+ERROR 42000: Incorrect column name 'FTS_DOC_İD'
+ALTER TABLE t1 ADD fts_doc_id INT, ALGORITHM=COPY;
+ERROR 42000: Incorrect column name 'fts_doc_id'
+ALTER TABLE t1 ADD fts_doc_id INT, ALGORITHM=INPLACE;
+ERROR 42000: Incorrect column name 'fts_doc_id'
+ALTER TABLE t1 ADD fts_doc_id BIGINT UNSIGNED NOT NULL, ALGORITHM=COPY;
+ERROR 42000: Incorrect column name 'fts_doc_id'
+ALTER TABLE t1 ADD fts_doc_id BIGINT UNSIGNED NOT NULL, ALGORITHM=INPLACE;
+ERROR 42000: Incorrect column name 'fts_doc_id'
+ALTER TABLE t1 ADD FTS_DOC_ID INT UNSIGNED NOT NULL, ALGORITHM=COPY;
+ERROR 42000: Incorrect column name 'FTS_DOC_ID'
+ALTER TABLE t1 ADD FTS_DOC_ID INT UNSIGNED NOT NULL, ALGORITHM=INPLACE;
+ERROR 42000: Incorrect column name 'FTS_DOC_ID'
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `f1` int(11) NOT NULL
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+DROP TABLE t1;

mysql-test/suite/innodb_fts/t/innodb-fts-ddl.test

@@ -278,3 +278,44 @@ CREATE TABLE t1 (FTS_DOC_ID BIGINT UNSIGNED PRIMARY KEY,
 		 f1 VARCHAR(200),FULLTEXT fidx(f1))engine=innodb;
 ALTER TABLE t1 DROP index fidx, ADD FULLTEXT INDEX(f1);
 DROP TABLE t1;
+
+--echo #
+--echo # MDEV-21478 Inplace alter fails to report error when
+--echo #	FTS_DOC_ID is added
+
+SET NAMES utf8;
+
+CREATE TABLE t1(f1 INT NOT NULL)ENGINE=InnoDB;
+ALTER TABLE t1 ADD FTS_DOC_ıD BIGINT UNSIGNED NOT NULL, ALGORITHM=COPY;
+ALTER TABLE t1 DROP COLUMN FTS_DOC_ıD;
+ALTER TABLE t1 ADD FTS_DOC_ıD BIGINT UNSIGNED NOT NULL, ALGORITHM=INPLACE;
+DROP TABLE t1;
+
+CREATE TABLE t1 (f1 INT NOT NULL)ENGINE=InnoDB;
+
+--error ER_WRONG_COLUMN_NAME
+ALTER TABLE t1 ADD FTS_DOC_İD BIGINT UNSIGNED NOT NULL, ALGORITHM=INPLACE;
+
+--error ER_WRONG_COLUMN_NAME
+ALTER TABLE t1 ADD FTS_DOC_İD BIGINT UNSIGNED NOT NULL, ALGORITHM=COPY;
+
+--error ER_WRONG_COLUMN_NAME
+ALTER TABLE t1 ADD fts_doc_id INT, ALGORITHM=COPY;
+
+--error ER_WRONG_COLUMN_NAME
+ALTER TABLE t1 ADD fts_doc_id INT, ALGORITHM=INPLACE;
+
+--error ER_WRONG_COLUMN_NAME
+ALTER TABLE t1 ADD fts_doc_id BIGINT UNSIGNED NOT NULL, ALGORITHM=COPY;
+
+--error ER_WRONG_COLUMN_NAME
+ALTER TABLE t1 ADD fts_doc_id BIGINT UNSIGNED NOT NULL, ALGORITHM=INPLACE;
+
+--error ER_WRONG_COLUMN_NAME
+ALTER TABLE t1 ADD FTS_DOC_ID INT UNSIGNED NOT NULL, ALGORITHM=COPY;
+
+--error ER_WRONG_COLUMN_NAME
+ALTER TABLE t1 ADD FTS_DOC_ID INT UNSIGNED NOT NULL, ALGORITHM=INPLACE;
+
+SHOW CREATE TABLE t1;
+DROP TABLE t1;

storage/innobase/handler/handler0alter.cc

@@ -4663,6 +4663,23 @@ prepare_inplace_alter_table_dict(
 				goto new_clustered_failed;
 			}
 
+			/** Note the FTS_DOC_ID name is case sensitive due
+			 to internal query parser.
+			 FTS_DOC_ID column must be of BIGINT NOT NULL type
+			 and it should be in all capitalized characters */
+			if (!innobase_strcasecmp(field->field_name,
+						 FTS_DOC_ID_COL_NAME)) {
+				if (col_type != DATA_INT
+				    || field->real_maybe_null()
+				    || col_len != sizeof(doc_id_t)
+				    || strcmp(field->field_name,
+					      FTS_DOC_ID_COL_NAME)) {
+					my_error(ER_WRONG_COLUMN_NAME, MYF(0),
+						 field->field_name);
+					goto new_clustered_failed;
+				}
+			}
+
 			if (is_virtual) {
 				dict_mem_table_add_v_col(
 					ctx->new_table, ctx->heap,