GEOMETRYCOLLECTION EMPTY handling fixed.

          The get_mbr() method shouldn't return the error, rather an invalid MBR
          in this case.

sql/item_geofunc.cc

@@ -559,8 +559,8 @@ longlong Item_func_spatial_mbr_rel::val_int()
 	args[1]->null_value ||
 	!(g1= Geometry::construct(&buffer1, res1->ptr(), res1->length())) ||
 	!(g2= Geometry::construct(&buffer2, res2->ptr(), res2->length())) ||
-	g1->get_mbr(&mbr1, &dummy) ||
-	g2->get_mbr(&mbr2, &dummy))))
+	g1->get_mbr(&mbr1, &dummy) || !mbr1.valid() ||
+	g2->get_mbr(&mbr2, &dummy) || !mbr2.valid())))
    return 0;
 
   switch (spatial_rel) {
@@ -686,8 +686,8 @@ longlong Item_func_spatial_rel::val_int()
        (args[0]->null_value || args[1]->null_value ||
 	!(g1= Geometry::construct(&buffer1, res1->ptr(), res1->length())) ||
 	!(g2= Geometry::construct(&buffer2, res2->ptr(), res2->length())) ||
-        g1->get_mbr(&mbr1, &c_end) ||
-        g2->get_mbr(&mbr2, &c_end))))
+        g1->get_mbr(&mbr1, &c_end) || !mbr1.valid() ||
+        g2->get_mbr(&mbr2, &c_end) || !mbr2.valid())))
     goto exit;
 
   umbr= mbr1;
@@ -824,8 +824,8 @@ String *Item_func_spatial_operation::val_str(String *str_value)
        (args[0]->null_value || args[1]->null_value ||
 	!(g1= Geometry::construct(&buffer1, res1->ptr(), res1->length())) ||
 	!(g2= Geometry::construct(&buffer2, res2->ptr(), res2->length())) ||
-        g1->get_mbr(&mbr1, &c_end) ||
-        g2->get_mbr(&mbr2, &c_end))))
+        g1->get_mbr(&mbr1, &c_end) || !mbr1.valid() ||
+        g2->get_mbr(&mbr2, &c_end) || !mbr2.valid())))
   {
     str_value= 0;
     goto exit;

sql/spatial.cc

@@ -308,6 +308,9 @@ bool Geometry::envelope(String *result) const
   const char *end;
 
   if (get_mbr(&mbr, &end))
+    return 1;
+
+  if (!mbr.valid())
   {
     /* Empty geometry */
     if (result->reserve(1 + 4*2))
@@ -2322,7 +2325,7 @@ bool Gis_geometry_collection::get_mbr(MBR *mbr, const char **end) const
   n_objects= uint4korr(data);
   data+= 4;
   if (n_objects == 0)
-    return 1;
+    goto exit;
 
   while (n_objects--)
   {
@@ -2339,6 +2342,7 @@ bool Gis_geometry_collection::get_mbr(MBR *mbr, const char **end) const
     if (geom->get_mbr(mbr, &data))
       return 1;
   }
+exit:
   *end= data;
   return 0;
 }
@@ -2356,10 +2360,11 @@ int Gis_geometry_collection::area(double *ar,  const char **end) const
     return 1;
   n_objects= uint4korr(data);
   data+= 4;
-  if (n_objects == 0)
-    return 1;
 
   result= 0.0;
+  if (n_objects == 0)
+    goto exit;
+
   while (n_objects--)
   {
     uint32 wkb_type;
@@ -2376,6 +2381,7 @@ int Gis_geometry_collection::area(double *ar,  const char **end) const
       return 1;
     result+= *ar;
   }
+exit:
   *end= data;
   *ar= result;
   return 0;
@@ -2394,10 +2400,11 @@ int Gis_geometry_collection::geom_length(double *len, const char **end) const
     return 1;
   n_objects= uint4korr(data);
   data+= 4;
+  result= 0.0;
+
   if (n_objects == 0)
-    return 1;
+    goto exit;
 
-  result= 0.0;
   while (n_objects--)
   {
     uint32 wkb_type;
@@ -2414,6 +2421,8 @@ int Gis_geometry_collection::geom_length(double *len, const char **end) const
       return 1;
     result+= *len;
   }
+
+exit:
   *end= data;
   *len= result;
   return 0;

sql/spatial.h

@@ -199,6 +199,9 @@ struct MBR
 
     return (d == intersection.dimension());
   }
+
+  int valid() const
+  { return xmin <= xmax && ymin <= ymax; }
 };