Merge branch '2018-09-13-radix-tree-bug'

diff --cc base/Makefile
index ff778157769f3a55c6b2ce508f8b7c80c00c696e,7b21ca5c7488a976b639dfd47fdad0cc321da69d..e30cb449847d1d57583c68c334a5721701b79c53
--- 1/base/Makefile
--- 2/base/Makefile
+++ b/base/Makefile
@@@ -11,8 -11,7 +11,8 @@@
  # Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  
  # Uncomment this to build the simple radix tree.  You'll need to make clean too.
- base/data-struct/radix-tree.o: CFLAGS += -DSIMPLE_RADIX_TREE
 +# Comment to build the advanced radix tree.
+ #base/data-struct/radix-tree.o: CFLAGS += -DSIMPLE_RADIX_TREE
  
  BASE_SOURCE=\
        base/data-struct/radix-tree.c \