Using Schema_specification_st instead of HA_CREATE_INFO in a few places

where the former is enough.

sql/log_event.cc

@@ -4058,7 +4058,7 @@ int Query_log_event::do_apply_event(rpl_group_info *rgi,
 {
   LEX_STRING new_db;
   int expected_error,actual_error= 0;
-  HA_CREATE_INFO db_options;
+  Schema_specification_st db_options;
   uint64 sub_id= 0;
   rpl_gtid gtid;
   Relay_log_info const *rli= rgi->rli;

sql/sql_parse.cc

@@ -4268,12 +4268,6 @@ end_with_restore_list:
     break;
   case SQLCOM_CREATE_DB:
   {
-    /*
-      As mysql_create_db() may modify HA_CREATE_INFO structure passed to
-      it, we need to use a copy of LEX::create_info to make execution
-      prepared statement- safe.
-    */
-    Schema_specification_st create_info(lex->create_info);
     if (check_db_name(&lex->name))
     {
       my_error(ER_WRONG_DB_NAME, MYF(0), lex->name.str);
@@ -4303,7 +4297,8 @@ end_with_restore_list:
                      lex->name.str, NULL, NULL, 1, 0))
       break;
     WSREP_TO_ISOLATION_BEGIN(lex->name.str, NULL, NULL)
-    res= mysql_create_db(thd, lex->name.str, lex->create_info, &create_info);
+    res= mysql_create_db(thd, lex->name.str,
+                         lex->create_info, &lex->create_info);
     break;
   }
   case SQLCOM_DROP_DB:
@@ -4375,7 +4370,6 @@ end_with_restore_list:
   case SQLCOM_ALTER_DB:
   {
     LEX_STRING *db= &lex->name;
-    HA_CREATE_INFO create_info(lex->create_info);
     if (check_db_name(db))
     {
       my_error(ER_WRONG_DB_NAME, MYF(0), db->str);
@@ -4403,7 +4397,7 @@ end_with_restore_list:
     if (check_access(thd, ALTER_ACL, db->str, NULL, NULL, 1, 0))
       break;
     WSREP_TO_ISOLATION_BEGIN(db->str, NULL, NULL)
-    res= mysql_alter_db(thd, db->str, &create_info);
+    res= mysql_alter_db(thd, db->str, &lex->create_info);
     break;
   }
   case SQLCOM_SHOW_CREATE_DB:

sql/sql_show.cc

@@ -1195,7 +1195,7 @@ bool mysqld_show_create_db(THD *thd, LEX_STRING *dbname,
   Security_context *sctx= thd->security_ctx;
   uint db_access;
 #endif
-  HA_CREATE_INFO create;
+  Schema_specification_st create;
   Protocol *protocol=thd->protocol;
   DBUG_ENTER("mysql_show_create_db");
 
@@ -4679,7 +4679,7 @@ int fill_schema_schemata(THD *thd, TABLE_LIST *tables, COND *cond)
 
   LOOKUP_FIELD_VALUES lookup_field_vals;
   Dynamic_array<LEX_STRING*> db_names;
-  HA_CREATE_INFO create;
+  Schema_specification_st create;
   TABLE *table= tables->table;
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
   Security_context *sctx= thd->security_ctx;

sql/sql_table.cc

@@ -4207,7 +4207,7 @@ static void set_table_default_charset(THD *thd,
   */
   if (!create_info->default_table_charset)
   {
-    HA_CREATE_INFO db_info;
+    Schema_specification_st db_info;
 
     load_db_opt_by_name(thd, db, &db_info);