bk commit into 5.0 tree (evgen:1.2095) BUG#17726

[eugene]

Below is the list of changes that have just been committed into a local
5.0 repository of evgen. When evgen does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
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ChangeSet
  1.2095 06/03/03 16:19:57 evgen@stripped +3 -0
  Fixed bug#17726: Not checked empty list caused endless loop
  
  When the Item_cond::fix_fields() function reduces cond tree, it in loop
  scans it's own list and when it founds Item_cond with same function (AND
  or OR) it does next things: 1) replaces that item with item's list. 2)
  empties item's list. Due to this operation is done twice - for update and
  for view, at the update phase cond's list of lower view is already empty.
  Empty list returns ref to itself, thus making endless loop by replacing
  list with itself, emptying, replacing again and so on. This results in
  server hung up.
  
  To the Item_cond::fix_fields() function added check that ensures that
  list being replaced with isn't empty.

  sql/item_cmpfunc.cc
    1.193 06/03/03 16:09:19 evgen@stripped +2 -1
    Fixed bug#17726: Not checked empty list caused endless loop
    To the Item_cond::fix_fields() function added check that ensures that
    list being replaced with isn't empty.

  mysql-test/r/view.result
    1.148 06/03/03 16:09:06 evgen@stripped +14 -0
    Added test for bug#17726: Not checked empty list caused endless loop

  mysql-test/t/view.test
    1.137 06/03/03 16:08:43 evgen@stripped +14 -0
    Added test for bug#17726: Not checked empty list caused endless loop

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	evgen
# Host:	moonbone.local
# Root:	/work/17726-bug-5.0-mysql

--- 1.192/sql/item_cmpfunc.cc	2006-03-01 14:48:52 +03:00
+++ 1.193/sql/item_cmpfunc.cc	2006-03-03 16:09:19 +03:00
@@ -2553,7 +2553,8 @@
   {
     table_map tmp_table_map;
     while (item->type() == Item::COND_ITEM &&
-	   ((Item_cond*) item)->functype() == functype())
+	   ((Item_cond*) item)->functype() == functype() &&
+           !((Item_cond*) item)->list.is_empty())
     {						// Identical function
       li.replace(((Item_cond*) item)->list);
       ((Item_cond*) item)->list.empty();

--- 1.147/mysql-test/r/view.result	2006-02-27 16:56:10 +03:00
+++ 1.148/mysql-test/r/view.result	2006-03-03 16:09:06 +03:00
@@ -2539,3 +2539,17 @@
 //
 View	Create View
 v1	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v1`
AS select sql_no_cache `test`.`t1`.`id` AS `id` from `t1`
+create table t1(f1 int, f2 int);
+create view v1 as select ta.f1 as a, tb.f1 as b from t1 ta, t1 tb where ta.f1=tb
+.f1 and ta.f2=tb.f2;
+insert into t1 values(1,1),(2,2);
+create view v2 as select * from v1 where a > 1 with check option;
+select * from v2;
+a	b
+2	2
+update v2 set b=3 where a=2;
+select * from v2;
+a	b
+3	3
+drop view v2, v1;
+drop table t1;

--- 1.136/mysql-test/t/view.test	2006-02-27 16:56:10 +03:00
+++ 1.137/mysql-test/t/view.test	2006-03-03 16:08:43 +03:00
@@ -2385,3 +2385,17 @@
 drop view v1;
 //
 delimiter ;//
+
+#
+# Bug#17726 Not checked empty list caused endless loop
+#
+create table t1(f1 int, f2 int);
+create view v1 as select ta.f1 as a, tb.f1 as b from t1 ta, t1 tb where ta.f1=tb
+.f1 and ta.f2=tb.f2;
+insert into t1 values(1,1),(2,2);
+create view v2 as select * from v1 where a > 1 with check option;
+select * from v2;
+update v2 set b=3 where a=2;
+select * from v2;
+drop view v2, v1;
+drop table t1;