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.

1 files changed, 7 insertions, 11 deletions

diff --git a/sql/item_geofunc.cc b/sql/item_geofunc.cc
index 6c012277888..966cefea9fe 100644
--- a/sql/item_geofunc.cc
+++ b/sql/item_geofunc.cc
@@ -27,7 +27,7 @@
 Field *Item_geometry_func::tmp_table_field(TABLE *t_arg)
 {
   return new Field_geom(max_length, maybe_null, name, t_arg,
-                        (Field::geometry_type) get_geometry_type());
+                        get_geometry_type());
 }
 
 void Item_geometry_func::fix_length_and_dec()
@@ -38,10 +38,6 @@ void Item_geometry_func::fix_length_and_dec()
   maybe_null= 1;
 }
 
-int Item_geometry_func::get_geometry_type() const
-{
-  return (int)Field::GEOM_GEOMETRY;
-}
 
 String *Item_func_geometry_from_text::val_str(String *str)
 {
@@ -160,9 +156,9 @@ String *Item_func_geometry_type::val_str(String *str)
 }
 
 
-int Item_func_envelope::get_geometry_type() const
+Field::geometry_type Item_func_envelope::get_geometry_type() const
 {
-  return (int) Field::GEOM_POLYGON;
+  return Field::GEOM_POLYGON;
 }
 
 
@@ -190,9 +186,9 @@ String *Item_func_envelope::val_str(String *str)
 }
 
 
-int Item_func_centroid::get_geometry_type() const
+Field::geometry_type Item_func_centroid::get_geometry_type() const
 {
-  return (int) Field::GEOM_POINT;
+  return Field::GEOM_POINT;
 }
 
 
@@ -330,9 +326,9 @@ err:
 */
 
 
-int Item_func_point::get_geometry_type() const
+Field::geometry_type Item_func_point::get_geometry_type() const
 {
-  return (int) Field::GEOM_POINT;
+  return Field::GEOM_POINT;
 }