Fix for bug#14945 "Truncate table doesn't reset the auto_increment

counter".

When TRUNCATE TABLE was called within an stored procedure the
auto_increment counter was not reset to 0 even if straight
TRUNCATE for this table did this.

This fix makes TRUNCATE in stored procedures to be handled exactly
in the same way as straight TRUNCATE. We achieve this by rolling
back the fix for bug 8850, which is no longer needed since stored
procedures don't require prelocked mode anymore (and TRUNCATE is
not allowed in stored functions or triggers).

mysql-test/r/sp.result

@@ -4811,6 +4811,17 @@ begin
 declare x int;
 select id from t1 order by x;
 end|
+drop procedure if exists bug14945|
+create table t3 (id int not null auto_increment primary key)|
+create procedure bug14945() deterministic truncate t3|
+insert into t3 values (null)|
+call bug14945()|
+insert into t3 values (null)|
+select * from t3|
+id
+1
+drop table t3|
+drop procedure bug14945|
 create procedure bug16474_2(x int)
 select id from t1 order by x|
 call bug16474_1()|

mysql-test/t/sp.test

@@ -5666,6 +5666,21 @@ begin
   select id from t1 order by x;
 end|
 
+# 
+# BUG#14945: Truncate table doesn't reset the auto_increment counter
+#
+--disable_warnings
+drop procedure if exists bug14945|
+--enable_warnings
+create table t3 (id int not null auto_increment primary key)|
+create procedure bug14945() deterministic truncate t3|
+insert into t3 values (null)|
+call bug14945()|
+insert into t3 values (null)|
+select * from t3|
+drop table t3|
+drop procedure bug14945|
+
 # This does NOT order by column index; variable is an expression.
 create procedure bug16474_2(x int)
   select id from t1 order by x|

sql/sql_delete.cc

@@ -842,8 +842,7 @@ bool mysql_truncate(THD *thd, TABLE_LIST *table_list, bool dont_send_ok)
                table_list->db, table_list->table_name);
       DBUG_RETURN(TRUE);
     }
-    if (!ha_check_storage_engine_flag(table_type, HTON_CAN_RECREATE)
-        || thd->lex->sphead)
+    if (!ha_check_storage_engine_flag(table_type, HTON_CAN_RECREATE))
       goto trunc_by_del;
     if (lock_and_wait_for_table_name(thd, table_list))
       DBUG_RETURN(TRUE);

sql/sql_parse.cc

@@ -3350,7 +3350,7 @@ end_with_restore_list:
       Don't allow this within a transaction because we want to use
       re-generate table
     */
-    if ((thd->locked_tables && !lex->sphead) || thd->active_transaction())
+    if (thd->locked_tables || thd->active_transaction())
     {
       my_message(ER_LOCK_OR_ACTIVE_TRANSACTION,
                  ER(ER_LOCK_OR_ACTIVE_TRANSACTION), MYF(0));