--- a/memory/build/rb.h
+++ b/memory/build/rb.h
@@ -664,36 +664,31 @@ private:
 #define rbp_f_height (3 * ((SIZEOF_PTR << 3) - (SIZEOF_PTR_2POW + 1)))
 
 #define rb_foreach_begin(a_type, a_field, a_tree, a_var)                       \
   {                                                                            \
     {                                                                          \
       /* Initialize the path to contain the left spine.             */         \
       a_type* rbp_f_path[rbp_f_height];                                        \
       a_type* rbp_f_node;                                                      \
-      bool rbp_f_synced = false;                                               \
       unsigned rbp_f_depth = 0;                                                \
       if ((a_tree)->rbt_root != &(a_tree)->rbt_nil) {                          \
         rbp_f_path[rbp_f_depth] = (a_tree)->rbt_root;                          \
         rbp_f_depth++;                                                         \
         while ((rbp_f_node = a_field(rbp_f_path[rbp_f_depth - 1]).Left()) !=   \
                &(a_tree)->rbt_nil) {                                           \
           rbp_f_path[rbp_f_depth] = rbp_f_node;                                \
           rbp_f_depth++;                                                       \
         }                                                                      \
       }                                                                        \
       /* While the path is non-empty, iterate.                      */         \
       while (rbp_f_depth > 0) {                                                \
         (a_var) = rbp_f_path[rbp_f_depth - 1];
 
 #define rb_foreach_end(a_type, a_field, a_tree, a_var)                         \
-  if (rbp_f_synced) {                                                          \
-    rbp_f_synced = false;                                                      \
-    continue;                                                                  \
-  }                                                                            \
   /* Find the successor.                                    */                 \
   if ((rbp_f_node = a_field(rbp_f_path[rbp_f_depth - 1]).Right()) !=           \
       &(a_tree)->rbt_nil) {                                                    \
     /* The successor is the left-most node in the right   */                   \
     /* subtree.                                           */                   \
     rbp_f_path[rbp_f_depth] = rbp_f_node;                                      \
     rbp_f_depth++;                                                             \
     while ((rbp_f_node = a_field(rbp_f_path[rbp_f_depth - 1]).Left()) !=       \