5.3 merge

mysql-test/r/gis.result

@@ -1546,6 +1546,12 @@ Warnings:
 Warning	1300	Invalid utf8 character string: 'E043'
 Warning	1300	Invalid utf8 character string: 'E043'
 drop table t1;
+#
+# MDEV-6883 ST_WITHIN crashes server if (0,0) is matched to POLYGON((0 0))
+#
+select st_within(GeomFromText('Polygon((0 0))'), Point(0,0));
+st_within(GeomFromText('Polygon((0 0))'), Point(0,0))
+1
 End of 5.3 tests
 #
 # Bug#11908153: CRASH AND/OR VALGRIND ERRORS IN FIELD_BLOB::GET_KEY_IMAGE

mysql-test/t/gis.test

@@ -1401,6 +1401,11 @@ insert into t1 values(geomfromtext("POINT(0 9.2233720368548e18)"));
 select equals(`a`,convert(`a` using utf8)) from `t1`;
 drop table t1;
 
+--echo #
+--echo # MDEV-6883 ST_WITHIN crashes server if (0,0) is matched to POLYGON((0 0))
+--echo #
+select st_within(GeomFromText('Polygon((0 0))'), Point(0,0));
+
 --echo End of 5.3 tests
 
 --echo #

sql/spatial.cc

@@ -1237,11 +1237,15 @@ int Gis_polygon::store_shapes(Gcalc_shape_transporter *trn) const
     trn->start_ring();
     get_point(&first_x, &first_y, data);
     data+= POINT_DATA_SIZE;
-    n_points--;
+
     prev_x= first_x;
     prev_y= first_y;
     if (trn->add_point(first_x, first_y))
       return 1;
+
+    if (--n_points == 0)
+      goto single_point_ring;
+
     while (--n_points)
     {
       double x, y;
@@ -1266,6 +1270,8 @@ int Gis_polygon::store_shapes(Gcalc_shape_transporter *trn) const
         return 1;
     }
     data+= POINT_DATA_SIZE;
+
+single_point_ring:
     trn->complete_ring();
   }