From eb9e174bc23fbc0eedb7db666b356233d0af1e69 Mon Sep 17 00:00:00 2001
From: "evgen@moonbone.local" <>
Date: Fri, 8 Jun 2007 00:33:03 +0400
Subject: Bug#28763: Selecting geometry fields in UNION caused server crash.

This bug was introduced by the fix for the bug#27300. In this fix a section
of code was added to the Item::tmp_table_field_from_field_type method.
This section intended to create Field_geom fields for the Item_geometry_func
class and its descendants. In order to get the geometry type of the current
item it casted "this" to the Item_geometry_func* type. But the
Item::tmp_table_field_from_field_type method is also used for creation of
fields for UNION and in this case this method is called for an object of the
Item_type_holder class and the cast to the Item_geometry_func* type causes
a server crash.

Now the Item::tmp_table_field_from_field_type method correctly works when it's
called for both the Item_type_holder and the Item_geometry_func classes.
The new geometry_type variable is added to the Item_type_holder class.
The new method called get_geometry_type is added to the Item_field
and the Field classes. It returns geometry type from the field for the
Item_field and the Field_geom classes and fails an assert for other Field
descendants.
---
 sql/item.h | 7 +++++++
 1 file changed, 7 insertions(+)

(limited to 'sql/item.h')

diff --git a/sql/item.h b/sql/item.h
index 11dce3a7758..96936f0ff88 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -1304,6 +1304,11 @@ public:
   int fix_outer_field(THD *thd, Field **field, Item **reference);
   virtual Item *update_value_transformer(byte *select_arg);
   void print(String *str);
+  Field::geometry_type get_geometry_type()
+  {
+    DBUG_ASSERT(field_type() == MYSQL_TYPE_GEOMETRY);
+    return field->get_geometry_type();
+  }
   friend class Item_default_value;
   friend class Item_insert_value;
   friend class st_select_lex_unit;
@@ -2563,6 +2568,7 @@ class Item_type_holder: public Item
 protected:
   TYPELIB *enum_set_typelib;
   enum_field_types fld_type;
+  Field::geometry_type geometry_type;
 
   void get_full_info(Item *item);
 
@@ -2582,6 +2588,7 @@ public:
   Field *make_field_by_type(TABLE *table);
   static uint32 display_length(Item *item);
   static enum_field_types get_real_type(Item *);
+  Field::geometry_type get_geometry_type() { return geometry_type; };
 };
 
 
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