bug 857066 Wrong result with ST_DISJOINT when using an index

        the ST_DISJOINT can't be properly optimized with the RTree key
        at the moment.

per-file comments:
  storage/maria/ma_rt_index.c
bug 857066 Wrong result with ST_DISJOINT when using an index
        disabled optimization for the DISJOINT case.

storage/maria/ma_rt_index.c

@@ -1258,7 +1258,7 @@ ha_rows maria_rtree_estimate(MARIA_HA *info, MARIA_KEY *key, uint32 flag)
   MARIA_PAGE page;
 
   if (flag & MBR_DISJOINT)
-    return info->state->records;
+    return HA_POS_ERROR;
 
   if ((root= share->state.key_root[key->keyinfo->key_nr]) == HA_OFFSET_ERROR)
     return HA_POS_ERROR;