Fixing bug #8850 in such a way that when TRUNCATE is called within

stored  procedure,  it  is converted  to DELETE.

.bzrignore

@@ -1105,3 +1105,4 @@ vio/test-ssl
 vio/test-sslclient
 vio/test-sslserver
 vio/viotest-ssl
+acinclude.m4

mysql-test/r/sp.result

@@ -2538,3 +2538,24 @@ drop procedure bug7992|
 drop table t3|
 drop table t1;
 drop table t2;
+drop procedure if exists sp1;
+create table t1 (a int) engine=innodb|
+create procedure sp1 ()
+begin
+truncate table t1; insert t1 values (1); rollback;
+end
+|
+begin;
+insert t1 values (2);
+call sp1();
+ERROR HY000: Can't execute the given command because you have active locked tables or an active transaction
+commit;
+select * from t1;
+a
+2
+call sp1();
+select * from t1;
+a
+1
+drop table t1;
+drop procedure sp1;

mysql-test/t/sp.test

@@ -3073,3 +3073,27 @@ delimiter ;|
 drop table t1;
 drop table t2;
 
+#
+# BUG#8850
+#
+--disable_warnings
+drop procedure if exists sp1;
+--enable_warnings
+delimiter |;
+create table t1 (a int) engine=innodb|
+create procedure sp1 ()
+begin
+  truncate table t1; insert t1 values (1); rollback;
+end
+|
+delimiter ;|
+begin;
+insert t1 values (2);
+--error 1192
+call sp1();
+commit;
+select * from t1;
+call sp1();
+select * from t1;
+drop table t1;
+drop procedure sp1;

sql/sql_delete.cc

@@ -749,11 +749,12 @@ 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_supports_generate(table_type))
+    if (!ha_supports_generate(table_type) || thd->lex->sphead)
     {
       /* Probably InnoDB table */
       table_list->lock_type= TL_WRITE;
       ha_enable_transaction(thd, FALSE);
+      mysql_init_select(thd->lex);
       error= mysql_delete(thd, table_list, (COND*) 0, (SQL_LIST*) 0,
 			  HA_POS_ERROR, 0);
       ha_enable_transaction(thd, TRUE);

sql/sql_parse.cc

@@ -3312,7 +3312,7 @@ mysql_execute_command(THD *thd)
       Don't allow this within a transaction because we want to use
       re-generate table
     */
-    if (thd->locked_tables || thd->active_transaction())
+    if ((thd->locked_tables && !lex->sphead) || thd->active_transaction())
     {
       my_message(ER_LOCK_OR_ACTIVE_TRANSACTION,
                  ER(ER_LOCK_OR_ACTIVE_TRANSACTION), MYF(0));