BUG#34768 - nondeterministic INSERT using LIMIT logged in stmt mode if

binlog_format=mixed

Statement-based replication of DELETE ... LIMIT, UPDATE ... LIMIT,
INSERT ... SELECT ... LIMIT is not safe as order of rows is not
defined.

With this fix, we issue a warning that this statement is not safe to
replicate in statement mode, or go to row-based mode in mixed mode.

Note that we may consider a statement as safe if ORDER BY primary_key
is present. However it may confuse users to see very similiar statements
replicated differently.

Note 2: regular UPDATE statement (w/o LIMIT) is unsafe as well, but
this patch doesn't address this issue. See comment from Kristian
posted 18 Mar 10:55.

mysql-test/suite/binlog/r/binlog_stm_ps.result

@@ -16,5 +16,6 @@ master-bin.000001	#	Query	#	#	use `test`; create table t1 (a int)
 master-bin.000001	#	User var	#	#	@`a`=98
 master-bin.000001	#	Query	#	#	use `test`; insert into t1 values (@a),(98)
 master-bin.000001	#	Query	#	#	use `test`; insert into t1 values (99)
-master-bin.000001	#	Query	#	#	use `test`; insert into t1 select 100 limit 100
+master-bin.000001	#	Table_map	#	#	table_id: # (test.t1)
+master-bin.000001	#	Write_rows	#	#	table_id: # flags: STMT_END_F
 drop table t1;

mysql-test/suite/binlog/r/binlog_unsafe.result

@@ -11,3 +11,31 @@ Level	Warning
 Code	1592
 Message	Statement is not safe to log in statement format.
 DROP TABLE t1,t2,t3;
+CREATE TABLE t1(a INT, b INT, KEY(a), PRIMARY KEY(b));
+INSERT INTO t1 SELECT * FROM t1 LIMIT 1;
+Warnings:
+Warning	1592	Statement is not safe to log in statement format.
+REPLACE INTO t1 SELECT * FROM t1 LIMIT 1;
+Warnings:
+Warning	1592	Statement is not safe to log in statement format.
+UPDATE t1 SET a=1 LIMIT 1;
+Warnings:
+Warning	1592	Statement is not safe to log in statement format.
+DELETE FROM t1 LIMIT 1;
+Warnings:
+Warning	1592	Statement is not safe to log in statement format.
+CREATE PROCEDURE p1()
+BEGIN
+INSERT INTO t1 SELECT * FROM t1 LIMIT 1;
+REPLACE INTO t1 SELECT * FROM t1 LIMIT 1;
+UPDATE t1 SET a=1 LIMIT 1;
+DELETE FROM t1 LIMIT 1;
+END|
+CALL p1();
+Warnings:
+Warning	1592	Statement is not safe to log in statement format.
+Warning	1592	Statement is not safe to log in statement format.
+Warning	1592	Statement is not safe to log in statement format.
+Warning	1592	Statement is not safe to log in statement format.
+DROP PROCEDURE p1;
+DROP TABLE t1;

mysql-test/suite/binlog/t/binlog_unsafe.test

@@ -15,4 +15,24 @@ query_vertical SHOW WARNINGS;
 
 DROP TABLE t1,t2,t3;
 
-
+#
+# BUG#34768 - nondeterministic INSERT using LIMIT logged in stmt mode if
+#             binlog_format=mixed
+#
+CREATE TABLE t1(a INT, b INT, KEY(a), PRIMARY KEY(b));
+INSERT INTO t1 SELECT * FROM t1 LIMIT 1;
+REPLACE INTO t1 SELECT * FROM t1 LIMIT 1;
+UPDATE t1 SET a=1 LIMIT 1;
+DELETE FROM t1 LIMIT 1;
+delimiter |;
+CREATE PROCEDURE p1()
+BEGIN
+  INSERT INTO t1 SELECT * FROM t1 LIMIT 1;
+  REPLACE INTO t1 SELECT * FROM t1 LIMIT 1;
+  UPDATE t1 SET a=1 LIMIT 1;
+  DELETE FROM t1 LIMIT 1;
+END|
+delimiter ;|
+CALL p1();
+DROP PROCEDURE p1;
+DROP TABLE t1;

sql/sql_delete.cc

@@ -418,6 +418,19 @@ bool mysql_prepare_delete(THD *thd, TABLE_LIST *table_list, Item **conds)
   DBUG_ENTER("mysql_prepare_delete");
   List<Item> all_fields;
 
+  /*
+    Statement-based replication of DELETE ... LIMIT is not safe as order of
+    rows is not defined, so in mixed mode we go to row-based.
+
+    Note that we may consider a statement as safe if ORDER BY primary_key
+    is present. However it may confuse users to see very similiar statements
+    replicated differently.
+  */
+  if (thd->lex->current_select->select_limit)
+  {
+    thd->lex->set_stmt_unsafe();
+    thd->set_current_stmt_binlog_row_based_if_mixed();
+  }
   thd->lex->allow_sum_func= 0;
   if (setup_tables_and_check_access(thd, &thd->lex->select_lex.context,
                                     &thd->lex->select_lex.top_join_list,

sql/sql_insert.cc

@@ -2763,6 +2763,19 @@ bool mysql_insert_select_prepare(THD *thd)
   TABLE_LIST *first_select_leaf_table;
   DBUG_ENTER("mysql_insert_select_prepare");
 
+  /*
+    Statement-based replication of INSERT ... SELECT ... LIMIT is not safe
+    as order of rows is not defined, so in mixed mode we go to row-based.
+
+    Note that we may consider a statement as safe if ORDER BY primary_key
+    is present or we SELECT a constant. However it may confuse users to
+    see very similiar statements replicated differently.
+  */
+  if (lex->current_select->select_limit)
+  {
+    lex->set_stmt_unsafe();
+    thd->set_current_stmt_binlog_row_based_if_mixed();
+  }
   /*
     SELECT_LEX do not belong to INSERT statement, so we can't add WHERE
     clause if table is VIEW

sql/sql_update.cc

@@ -859,6 +859,19 @@ bool mysql_prepare_update(THD *thd, TABLE_LIST *table_list,
   SELECT_LEX *select_lex= &thd->lex->select_lex;
   DBUG_ENTER("mysql_prepare_update");
 
+  /*
+    Statement-based replication of UPDATE ... LIMIT is not safe as order of
+    rows is not defined, so in mixed mode we go to row-based.
+
+    Note that we may consider a statement as safe if ORDER BY primary_key
+    is present. However it may confuse users to see very similiar statements
+    replicated differently.
+  */
+  if (thd->lex->current_select->select_limit)
+  {
+    thd->lex->set_stmt_unsafe();
+    thd->set_current_stmt_binlog_row_based_if_mixed();
+  }
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
   table_list->grant.want_privilege= table->grant.want_privilege= 
     (SELECT_ACL & ~table->grant.privilege);