Followup: BUG#23479595 SEGMENTATION FAULT WHEN SELECT FTS INDEX TABLES IN INFORMATION SCHEMA

BUG#23742339 FAILING ASSERTION: SYM_NODE->TABLE != NULL

Analysis: When we access fts aux tables in information schema,the
fts aux tables are dropped by DROP DATABASE in another session.

Solution: Drop parent table if it's a fts aux table, and drop
table will drop fts aux tables together.
Reviewed-by: Jimmy Yang <jimmy.yang@oracle.com>
RB: 13264

storage/innobase/fts/fts0fts.cc

@@ -6497,6 +6497,36 @@ fts_check_corrupt_index(
 	return(0);
 }
 
+/* Get parent table name if it's a fts aux table
+@param[in]	aux_table_name	aux table name
+@param[in]	aux_table_len	aux table length
+@return parent table name, or NULL */
+char*
+fts_get_parent_table_name(
+	const char*	aux_table_name,
+	ulint		aux_table_len)
+{
+	fts_aux_table_t	aux_table;
+	char*		parent_table_name = NULL;
+
+	if (fts_is_aux_table_name(&aux_table, aux_table_name, aux_table_len)) {
+		dict_table_t*	parent_table;
+
+		parent_table = dict_table_open_on_id(
+			aux_table.parent_id, TRUE, DICT_TABLE_OP_NORMAL);
+
+		if (parent_table != NULL) {
+			parent_table_name = mem_strdupl(
+				parent_table->name.m_name,
+				strlen(parent_table->name.m_name));
+
+			dict_table_close(parent_table, TRUE, FALSE);
+		}
+	}
+
+	return(parent_table_name);
+}
+
 /** Check the validity of the parent table.
 @param[in]	aux_table	auxiliary table
 @return true if it is a valid table or false if it is not */

storage/innobase/include/fts0fts.h

@@ -843,6 +843,15 @@ fts_init_doc_id(
 /*============*/
 	const dict_table_t*		table);	/*!< in: table */
 
+/* Get parent table name if it's a fts aux table
+@param[in]	aux_table_name	aux table name
+@param[in]	aux_table_len	aux table length
+@return parent table name, or NULL */
+char*
+fts_get_parent_table_name(
+	const char*	aux_table_name,
+	ulint		aux_table_len);
+
 /******************************************************************//**
 compare two character string according to their charset. */
 extern

storage/innobase/row/row0mysql.cc

@@ -4293,6 +4293,19 @@ row_drop_database_for_mysql(
 	row_mysql_lock_data_dictionary(trx);
 
 	while ((table_name = dict_get_first_table_name_in_db(name))) {
+		/* Drop parent table if it is a fts aux table, to
+		avoid accessing dropped fts aux tables in information
+		scheam when parent table still exists.
+		Note: Drop parent table will drop fts aux tables. */
+		char*	parent_table_name;
+		parent_table_name = fts_get_parent_table_name(
+				table_name, strlen(table_name));
+
+		if (parent_table_name != NULL) {
+			ut_free(table_name);
+			table_name = parent_table_name;
+		}
+
 		ut_a(memcmp(table_name, name, namelen) == 0);
 
 		table = dict_table_open_on_name(