Bug#24478 DROP TRIGGER is not caught by replicate-*-table filters

Problem: DROP TRIGGER was not properly handled in combination
with slave filters, which made replication stop
Fix: loading table name before checking slave filters when
dropping a trigger.


mysql-test/r/rpl_replicate_do.result:
  Adding test case
mysql-test/t/rpl_replicate_do.test:
  Adding test case
sql/sql_parse.cc:
  Loading table name when dropping a trigger
  before checking slave filtering rules.
sql/sql_trigger.cc:
  Making add_table_for_trigger() public
sql/sql_trigger.h:
  Making add_table_for_trigger() public

mysql-test/r/rpl_replicate_do.result

@@ -41,3 +41,37 @@ select * from t1;
 ts
 2005-08-12 00:00:00
 drop table t1;
+*** master ***
+create table t1 (a int, b int);
+create trigger trg1 before insert on t1 for each row set new.b=2;
+create table t2 (a int, b int);
+create trigger trg2 before insert on t2 for each row set new.b=2;
+show tables;
+Tables_in_test
+t1
+t2
+show triggers;
+Trigger	Event	Table	Statement	Timing	Created	sql_mode	Definer
+trg1	INSERT	t1	set new.b=2	BEFORE	NULL		root@localhost
+trg2	INSERT	t2	set new.b=2	BEFORE	NULL		root@localhost
+*** slave ***
+show tables;
+Tables_in_test
+t1
+show triggers;
+Trigger	Event	Table	Statement	Timing	Created	sql_mode	Definer
+trg1	INSERT	t1	set new.b=2	BEFORE	NULL		root@localhost
+*** master ***
+drop trigger trg1;
+drop trigger trg2;
+show triggers;
+Trigger	Event	Table	Statement	Timing	Created	sql_mode	Definer
+*** slave ***
+show tables;
+Tables_in_test
+t1
+show triggers;
+Trigger	Event	Table	Statement	Timing	Created	sql_mode	Definer
+*** master ***
+drop table t1;
+drop table t2;

mysql-test/t/rpl_replicate_do.test

@@ -59,3 +59,35 @@ drop table t1;
 sync_slave_with_master;
 
 # End of 4.1 tests
+
+#
+# Bug#24478 DROP TRIGGER is not caught by replicate-*-table filters
+#
+--echo *** master ***
+connection master;
+create table t1 (a int, b int);
+create trigger trg1 before insert on t1 for each row set new.b=2;
+create table t2 (a int, b int);
+create trigger trg2 before insert on t2 for each row set new.b=2;
+show tables;
+show triggers;
+sync_slave_with_master;
+--echo *** slave ***
+connection slave;
+show tables;
+show triggers;
+--echo *** master ***
+connection master;
+drop trigger trg1;
+drop trigger trg2;
+show triggers;
+sync_slave_with_master;
+--echo *** slave ***
+connection slave;
+show tables;
+show triggers;
+--echo *** master ***
+connection master;
+drop table t1;
+drop table t2;
+sync_slave_with_master;

sql/sql_parse.cc

@@ -33,6 +33,7 @@
 #include "sp_head.h"
 #include "sp.h"
 #include "sp_cache.h"
+#include "sql_trigger.h"
 
 #ifdef HAVE_OPENSSL
 /*
@@ -2485,6 +2486,30 @@ mysql_execute_command(THD *thd)
 #ifdef HAVE_REPLICATION
   if (unlikely(thd->slave_thread))
   {
+    if (lex->sql_command == SQLCOM_DROP_TRIGGER)
+    {
+      /*
+        When dropping a trigger, we need to load its table name
+        before checking slave filter rules.
+      */
+      add_table_for_trigger(thd, thd->lex->spname, 1, &all_tables);
+      
+      if (!all_tables)
+      {
+        /*
+          If table name cannot be loaded,
+          it means the trigger does not exists possibly because
+          CREATE TRIGGER was previously skipped for this trigger
+          according to slave filtering rules.
+          Returning success without producing any errors in this case.
+        */
+        DBUG_RETURN(0);
+      }
+      
+      // force searching in slave.cc:tables_ok() 
+      all_tables->updating= 1;
+    }
+    
     /*
       Check if statment should be skipped because of slave filtering
       rules

sql/sql_trigger.cc

@@ -107,10 +107,6 @@ const LEX_STRING trg_event_type_names[]=
 };
 
 
-static int
-add_table_for_trigger(THD *thd, sp_name *trig, bool if_exists,
-                      TABLE_LIST ** table);
-
 class Handle_old_incorrect_sql_modes_hook: public Unknown_key_hook
 {
 private:
@@ -1183,7 +1179,7 @@ bool Table_triggers_list::get_trigger_info(THD *thd, trg_event_type event,
     1 Error
 */
 
-static int
+int
 add_table_for_trigger(THD *thd, sp_name *trig, bool if_exists,
                       TABLE_LIST **table)
 {

sql/sql_trigger.h

@@ -139,3 +139,7 @@ class Table_triggers_list: public Sql_alloc
 
 extern const LEX_STRING trg_action_time_type_names[];
 extern const LEX_STRING trg_event_type_names[];
+
+int
+add_table_for_trigger(THD *thd, sp_name *trig, bool if_exists,
+                      TABLE_LIST **table);