Bug #31155 gis types in union'd select cause crash.

We use get_geometry_type() call to decide the exact type
of a geometry field to be created (POINT, POLYGON etc)
Though this function was only implemented for few items.
In the bug's case we need to call this function for the
Item_sum instance, where it was not implemented, what is
the reason of the crash.
Fixed by implementing virtual Item::get_geometry_type(),
so it can be called for any Item.


sql/item.h:
  Bug #31155 gis types in union'd select cause crash.
  virtual Item::geometry_type() added instead of
  various geometry_type() fucntions.
sql/item.cc:
  Bug #31155 gis types in union'd select cause crash.
  
  Unified virtual ::get_geometry_type() function used
sql/item_geofunc.cc:
  Bug #31155 gis types in union'd select cause crash.
  
  virtual Item::geometry_type() implemented for geo-Items.
  Mostly previous ::get_geometry_type() implementation changed
sql/item_geofunc.h:
  Bug #31155 gis types in union'd select cause crash.
  
  get_geometry_type() declarations unified

1 files changed, 3 insertions, 8 deletions

diff --git a/sql/item.cc b/sql/item.cc
index e9b2904e3da..997ad0972db 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -4364,11 +4364,8 @@ Field *Item::tmp_table_field_from_field_type(TABLE *table)
                           collation.collation);
     break;					// Blob handled outside of case
   case MYSQL_TYPE_GEOMETRY:
-    return new Field_geom(max_length, maybe_null, name, table,
-                          (Field::geometry_type)
-                          ((type() == Item::TYPE_HOLDER) ?
-                           ((Item_type_holder *)this)->get_geometry_type() :
-                           ((Item_geometry_func *)this)->get_geometry_type()));
+    return new Field_geom(max_length, maybe_null,
+                          name, table, get_geometry_type());
   }
 }
 
@@ -6489,9 +6486,7 @@ Item_type_holder::Item_type_holder(THD *thd, Item *item)
     decimals= 0;
   prev_decimal_int_part= item->decimal_int_part();
   if (item->field_type() == MYSQL_TYPE_GEOMETRY)
-    geometry_type= (item->type() == Item::FIELD_ITEM) ?
-      ((Item_field *)item)->get_geometry_type() :
-      (Field::geometry_type)((Item_geometry_func *)item)->get_geometry_type();
+    geometry_type= item->get_geometry_type();
 }