MDEV-37744 Table Charset Mismatch (Primary/Replica) via Event

Events should use proper mysql_change_db() to configure the current
database correctly, in particular to set the db_charset.

Author: vuvova

mysql-test/main/events_2.result

@@ -437,3 +437,27 @@ Warnings:
 Note	1544	Event execution time is in the past. Event has been disabled
 drop event event_35981;
 drop database events_test;
+#
+# MDEV-37744 Table Charset Mismatch (Primary/Replica) via Event
+#
+set global event_scheduler=1;
+create schema andre default charset utf8mb4 collate utf8mb4_general_ci;
+use andre;
+create event daily_table_creation
+on schedule every 1 day starts now() + interval 5 second do
+create table andre_table (
+id int(11) not null auto_increment primary key,
+col_1 varchar(50) not null
+);
+show create table andre_table;
+Table	Create Table
+andre_table	CREATE TABLE `andre_table` (
+  `id` int(11) NOT NULL AUTO_INCREMENT,
+  `col_1` varchar(50) NOT NULL,
+  PRIMARY KEY (`id`)
+) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci
+set global event_scheduler=0;
+drop event daily_table_creation;
+drop schema andre;
+use test;
+# End of 10.11 tests

mysql-test/main/events_2.test

@@ -526,3 +526,26 @@ let $wait_condition=
 
 drop database events_test;
 --enable_service_connection
+
+--echo #
+--echo # MDEV-37744 Table Charset Mismatch (Primary/Replica) via Event
+--echo #
+set global event_scheduler=1;
+create schema andre default charset utf8mb4 collate utf8mb4_general_ci;
+use andre;
+create event daily_table_creation
+on schedule every 1 day starts now() + interval 5 second do
+ create table andre_table (
+     id int(11) not null auto_increment primary key,
+     col_1 varchar(50) not null
+   );
+
+let $wait_condition= select count(*)= 1 from information_schema.tables where table_name = 'andre_table';
+source include/wait_condition.inc;
+show create table andre_table;
+set global event_scheduler=0;
+drop event daily_table_creation;
+drop schema andre;
+use test;
+
+--echo # End of 10.11 tests

sql/event_data_objects.cc

@@ -1371,30 +1371,13 @@ Event_job_data::execute(THD *thd, bool drop)
   wsrep_open(thd);
   wsrep_before_command(thd);
 #endif /* WITH_WSREP */
-  /*
-    MySQL parser currently assumes that current database is either
-    present in THD or all names in all statements are fully specified.
-    And yet not fully specified names inside stored programs must be 
-    be supported, even if the current database is not set:
-    CREATE PROCEDURE db1.p1() BEGIN CREATE TABLE t1; END//
-    -- in this example t1 should be always created in db1 and the statement
-    must parse even if there is no current database.
-
-    To support this feature and still address the parser limitation,
-    we need to set the current database here.
-    We don't have to call mysql_change_db, since the checks performed
-    in it are unnecessary for the purpose of parsing, and
-    mysql_change_db will be invoked anyway later, to activate the
-    procedure database before it's executed.
-  */
-  thd->set_db(&dbname);
 
   lex_start(thd);
 
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
-  if (event_sctx.change_security_context(thd,
-                                         &definer_user, &definer_host,
-                                         &dbname, &save_sctx))
+  if (event_sctx.change_security_context(thd, &definer_user, &definer_host,
+                                         &dbname, &save_sctx) ||
+      mysql_change_db(thd, &dbname, false))
   {
     sql_print_error("Event Scheduler: "
                     "[%s].[%s.%s] execution failed, "