install-reloc: Support multi-binary installation.
[gnulib.git] / lib / gl_anyavltree_list2.h
index a4c26c5..90a2b0f 100644 (file)
@@ -1,11 +1,11 @@
 /* Sequential list data type implemented by a binary tree.
-   Copyright (C) 2006 Free Software Foundation, Inc.
+   Copyright (C) 2006-2007, 2009-2013 Free Software Foundation, Inc.
    Written by Bruno Haible <bruno@clisp.org>, 2006.
 
-   This program is free software; you can redistribute it and/or modify
+   This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software Foundation,
-   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 /* Common code of gl_avltree_list.c and gl_avltreehash_list.c.  */
 
 /* -------------------------- gl_list_t Data Type -------------------------- */
 
 /* Create a subtree for count >= 1 elements.
-   Its height is h where 2^(h-1) <= count <= 2^h - 1.  */
+   Its height is h where 2^(h-1) <= count <= 2^h - 1.
+   Return NULL upon out-of-memory.  */
 static gl_list_node_t
 create_subtree_with_contents (size_t count, const void **contents)
 {
@@ -29,11 +29,15 @@ create_subtree_with_contents (size_t count, const void **contents)
   size_t half2 = count / 2;
   /* Note: half1 + half2 = count - 1.  */
   gl_list_node_t node =
-    (struct gl_list_node_impl *) xmalloc (sizeof (struct gl_list_node_impl));
+    (struct gl_list_node_impl *) malloc (sizeof (struct gl_list_node_impl));
+  if (node == NULL)
+    return NULL;
 
   if (half1 > 0)
     {
       node->left = create_subtree_with_contents (half1, contents);
+      if (node->left == NULL)
+        goto fail1;
       node->left->parent = node;
     }
   else
@@ -44,6 +48,8 @@ create_subtree_with_contents (size_t count, const void **contents)
   if (half2 > 0)
     {
       node->right = create_subtree_with_contents (half2, contents + half1 + 1);
+      if (node->right == NULL)
+        goto fail2;
       node->right->parent = node;
     }
   else
@@ -58,21 +64,33 @@ create_subtree_with_contents (size_t count, const void **contents)
   node->branch_size = count;
 
   return node;
+
+ fail2:
+  if (node->left != NULL)
+    free_subtree (node->left);
+ fail1:
+  free (node);
+  return NULL;
 }
 
 static gl_list_t
-gl_tree_create (gl_list_implementation_t implementation,
-               gl_listelement_equals_fn equals_fn,
-               gl_listelement_hashcode_fn hashcode_fn,
-               bool allow_duplicates,
-               size_t count, const void **contents)
+gl_tree_nx_create (gl_list_implementation_t implementation,
+                   gl_listelement_equals_fn equals_fn,
+                   gl_listelement_hashcode_fn hashcode_fn,
+                   gl_listelement_dispose_fn dispose_fn,
+                   bool allow_duplicates,
+                   size_t count, const void **contents)
 {
   struct gl_list_impl *list =
-    (struct gl_list_impl *) xmalloc (sizeof (struct gl_list_impl));
+    (struct gl_list_impl *) malloc (sizeof (struct gl_list_impl));
+
+  if (list == NULL)
+    return NULL;
 
   list->base.vtable = implementation;
   list->base.equals_fn = equals_fn;
   list->base.hashcode_fn = hashcode_fn;
+  list->base.dispose_fn = dispose_fn;
   list->base.allow_duplicates = allow_duplicates;
 #if WITH_HASHTABLE
   {
@@ -80,25 +98,44 @@ gl_tree_create (gl_list_implementation_t implementation,
     if (estimate < 10)
       estimate = 10;
     list->table_size = next_prime (estimate);
+    if (size_overflow_p (xtimes (list->table_size, sizeof (gl_hash_entry_t))))
+      goto fail1;
     list->table =
-      (gl_hash_entry_t *) xzalloc (list->table_size * sizeof (gl_hash_entry_t));
+      (gl_hash_entry_t *) calloc (list->table_size, sizeof (gl_hash_entry_t));
+    if (list->table == NULL)
+      goto fail1;
   }
 #endif
   if (count > 0)
     {
       list->root = create_subtree_with_contents (count, contents);
+      if (list->root == NULL)
+        goto fail2;
       list->root->parent = NULL;
 
 #if WITH_HASHTABLE
       /* Now that the tree is built, node_position() works.  Now we can
-        add the nodes to the hash table.  */
-      add_nodes_to_buckets (list);
+         add the nodes to the hash table.  */
+      if (add_nodes_to_buckets (list) < 0)
+        goto fail3;
 #endif
     }
   else
     list->root = NULL;
 
   return list;
+
+#if WITH_HASHTABLE
+ fail3:
+  free_subtree (list->root);
+#endif
+ fail2:
+#if WITH_HASHTABLE
+  free (list->table);
+ fail1:
+#endif
+  free (list);
+  return NULL;
 }
 
 /* Ensure the tree is balanced, after an insertion or deletion operation.
@@ -107,7 +144,7 @@ gl_tree_create (gl_list_implementation_t implementation,
    Rotation operations are performed starting at PARENT (not NODE itself!).  */
 static void
 rebalance (gl_list_t list,
-          gl_list_node_t node, int height_diff, gl_list_node_t parent)
+           gl_list_node_t node, int height_diff, gl_list_node_t parent)
 {
   for (;;)
     {
@@ -123,259 +160,389 @@ rebalance (gl_list_t list,
       previous_balance = node->balance;
 
       /* The balance of NODE is incremented by BALANCE_DIFF: +1 if the right
-        branch's height has increased by 1 or the left branch's height has
-        decreased by 1, -1 if the right branch's height has decreased by 1 or
-        the left branch's height has increased by 1, 0 if no height change.  */
+         branch's height has increased by 1 or the left branch's height has
+         decreased by 1, -1 if the right branch's height has decreased by 1 or
+         the left branch's height has increased by 1, 0 if no height change.  */
       if (node->left != NULL || node->right != NULL)
-       balance_diff = (child == node->right ? height_diff : -height_diff);
+        balance_diff = (child == node->right ? height_diff : -height_diff);
       else
-       /* Special case where above formula doesn't work, because the caller
-          didn't tell whether node's left or right branch shrunk from height 1
-          to NULL.  */
-       balance_diff = - previous_balance;
+        /* Special case where above formula doesn't work, because the caller
+           didn't tell whether node's left or right branch shrunk from height 1
+           to NULL.  */
+        balance_diff = - previous_balance;
 
       node->balance += balance_diff;
       if (balance_diff == previous_balance)
-       {
-         /* node->balance is outside the range [-1,1].  Must rotate.  */
-         gl_list_node_t *nodep;
-
-         if (node->parent == NULL)
-           /* node == list->root */
-           nodep = &list->root;
-         else if (node->parent->left == node)
-           nodep = &node->parent->left;
-         else if (node->parent->right == node)
-           nodep = &node->parent->right;
-         else
-           abort ();
-
-         nodeleft = node->left;
-         noderight = node->right;
-
-         if (balance_diff < 0)
-           {
-             /* node->balance = -2.  The subtree is heavier on the left side.
-                Rotate from left to right:
-
-                                 *
-                               /   \
-                            h+2      h
-              */
-             gl_list_node_t nodeleftleft = nodeleft->left;
-             gl_list_node_t nodeleftright = nodeleft->right;
-             if (nodeleft->balance <= 0)
-               {
-                 /*
-                             *                    h+2|h+3
-                           /   \                  /    \
-                        h+2      h      -->      /   h+1|h+2
-                        / \                      |    /    \
-                      h+1 h|h+1                 h+1  h|h+1  h
-                  */
-                 node->left = nodeleftright;
-                 nodeleft->right = node;
-
-                 nodeleft->parent = node->parent;
-                 node->parent = nodeleft;
-                 if (nodeleftright != NULL)
-                   nodeleftright->parent = node;
-
-                 nodeleft->balance += 1;
-                 node->balance = - nodeleft->balance;
-
-                 node->branch_size =
-                   (nodeleftright != NULL ? nodeleftright->branch_size : 0)
-                   + 1 + (noderight != NULL ? noderight->branch_size : 0);
-                 nodeleft->branch_size =
-                   nodeleftleft->branch_size + 1 + node->branch_size;
-
-                 *nodep = nodeleft;
-                 height_diff = (height_diff < 0
-                                ? /* noderight's height had been decremented from
-                                     h+1 to h.  The subtree's height changes from
-                                     h+3 to h+2|h+3.  */
-                                  nodeleft->balance - 1
-                                : /* nodeleft's height had been incremented from
-                                     h+1 to h+2.  The subtree's height changes from
-                                     h+2 to h+2|h+3.  */
-                                  nodeleft->balance);
-               }
-             else
-               {
-                 /*
-                           *                     h+2
-                         /   \                 /     \
-                      h+2      h      -->    h+1     h+1
-                      / \                    / \     / \
-                     h  h+1                 h   L   R   h
-                        / \
-                       L   R
-
-                  */
-                 gl_list_node_t L = nodeleft->right = nodeleftright->left;
-                 gl_list_node_t R = node->left = nodeleftright->right;
-                 nodeleftright->left = nodeleft;
-                 nodeleftright->right = node;
-
-                 nodeleftright->parent = node->parent;
-                 if (L != NULL)
-                   L->parent = nodeleft;
-                 if (R != NULL)
-                   R->parent = node;
-                 nodeleft->parent = nodeleftright;
-                 node->parent = nodeleftright;
-
-                 nodeleft->balance = (nodeleftright->balance > 0 ? -1 : 0);
-                 node->balance = (nodeleftright->balance < 0 ? 1 : 0);
-                 nodeleftright->balance = 0;
-
-                 nodeleft->branch_size =
-                   (nodeleft->left != NULL ? nodeleft->left->branch_size : 0)
-                   + 1 + (nodeleft->right != NULL ? nodeleft->right->branch_size : 0);
-                 node->branch_size =
-                   (node->left != NULL ? node->left->branch_size : 0)
-                   + 1 + (node->right != NULL ? node->right->branch_size : 0);
-                 nodeleftright->branch_size =
-                   nodeleft->branch_size + 1 + node->branch_size;
-
-                 *nodep = nodeleftright;
-                 height_diff = (height_diff < 0
-                                ? /* noderight's height had been decremented from
-                                     h+1 to h.  The subtree's height changes from
-                                     h+3 to h+2.  */
-                                  -1
-                                : /* nodeleft's height had been incremented from
-                                     h+1 to h+2.  The subtree's height changes from
-                                     h+2 to h+2.  */
-                                  0);
-               }
-           }
-         else
-           {
-             /* node->balance = 2.  The subtree is heavier on the right side.
-                Rotate from right to left:
-
-                                 *
-                               /   \
-                             h      h+2
-              */
-             gl_list_node_t noderightleft = noderight->left;
-             gl_list_node_t noderightright = noderight->right;
-             if (noderight->balance >= 0)
-               {
-                 /*
-                             *                    h+2|h+3
-                           /   \                   /    \
-                         h      h+2     -->    h+1|h+2   \
-                                / \            /    \    |
-                            h|h+1 h+1         h   h|h+1 h+1
-                  */
-                 node->right = noderightleft;
-                 noderight->left = node;
-
-                 noderight->parent = node->parent;
-                 node->parent = noderight;
-                 if (noderightleft != NULL)
-                   noderightleft->parent = node;
-
-                 noderight->balance -= 1;
-                 node->balance = - noderight->balance;
-
-                 node->branch_size =
-                   (nodeleft != NULL ? nodeleft->branch_size : 0)
-                   + 1 + (noderightleft != NULL ? noderightleft->branch_size : 0);
-                 noderight->branch_size =
-                   node->branch_size + 1 + noderightright->branch_size;
-
-                 *nodep = noderight;
-                 height_diff = (height_diff < 0
-                                ? /* nodeleft's height had been decremented from
-                                     h+1 to h.  The subtree's height changes from
-                                     h+3 to h+2|h+3.  */
-                                  - noderight->balance - 1
-                                : /* noderight's height had been incremented from
-                                     h+1 to h+2.  The subtree's height changes from
-                                     h+2 to h+2|h+3.  */
-                                  - noderight->balance);
-               }
-             else
-               {
-                 /*
-                           *                    h+2
-                         /   \                /     \
-                       h      h+2    -->    h+1     h+1
-                              / \           / \     / \
-                            h+1  h         h   L   R   h
-                            / \
-                           L   R
-
-                  */
-                 gl_list_node_t L = node->right = noderightleft->left;
-                 gl_list_node_t R = noderight->left = noderightleft->right;
-                 noderightleft->left = node;
-                 noderightleft->right = noderight;
-
-                 noderightleft->parent = node->parent;
-                 if (L != NULL)
-                   L->parent = node;
-                 if (R != NULL)
-                   R->parent = noderight;
-                 node->parent = noderightleft;
-                 noderight->parent = noderightleft;
-
-                 node->balance = (noderightleft->balance > 0 ? -1 : 0);
-                 noderight->balance = (noderightleft->balance < 0 ? 1 : 0);
-                 noderightleft->balance = 0;
-
-                 node->branch_size =
-                   (node->left != NULL ? node->left->branch_size : 0)
-                   + 1 + (node->right != NULL ? node->right->branch_size : 0);
-                 noderight->branch_size =
-                   (noderight->left != NULL ? noderight->left->branch_size : 0)
-                   + 1 + (noderight->right != NULL ? noderight->right->branch_size : 0);
-                 noderightleft->branch_size =
-                   node->branch_size + 1 + noderight->branch_size;
-
-                 *nodep = noderightleft;
-                 height_diff = (height_diff < 0
-                                ? /* nodeleft's height had been decremented from
-                                     h+1 to h.  The subtree's height changes from
-                                     h+3 to h+2.  */
-                                  -1
-                                : /* noderight's height had been incremented from
-                                     h+1 to h+2.  The subtree's height changes from
-                                     h+2 to h+2.  */
-                                  0);
-               }
-           }
-         node = *nodep;
-       }
+        {
+          /* node->balance is outside the range [-1,1].  Must rotate.  */
+          gl_list_node_t *nodep;
+
+          if (node->parent == NULL)
+            /* node == list->root */
+            nodep = &list->root;
+          else if (node->parent->left == node)
+            nodep = &node->parent->left;
+          else if (node->parent->right == node)
+            nodep = &node->parent->right;
+          else
+            abort ();
+
+          nodeleft = node->left;
+          noderight = node->right;
+
+          if (balance_diff < 0)
+            {
+              /* node->balance = -2.  The subtree is heavier on the left side.
+                 Rotate from left to right:
+
+                                  *
+                                /   \
+                             h+2      h
+               */
+              gl_list_node_t nodeleftleft = nodeleft->left;
+              gl_list_node_t nodeleftright = nodeleft->right;
+              if (nodeleft->balance <= 0)
+                {
+                  /*
+                              *                    h+2|h+3
+                            /   \                  /    \
+                         h+2      h      -->      /   h+1|h+2
+                         / \                      |    /    \
+                       h+1 h|h+1                 h+1  h|h+1  h
+                   */
+                  node->left = nodeleftright;
+                  nodeleft->right = node;
+
+                  nodeleft->parent = node->parent;
+                  node->parent = nodeleft;
+                  if (nodeleftright != NULL)
+                    nodeleftright->parent = node;
+
+                  nodeleft->balance += 1;
+                  node->balance = - nodeleft->balance;
+
+                  node->branch_size =
+                    (nodeleftright != NULL ? nodeleftright->branch_size : 0)
+                    + 1 + (noderight != NULL ? noderight->branch_size : 0);
+                  nodeleft->branch_size =
+                    nodeleftleft->branch_size + 1 + node->branch_size;
+
+                  *nodep = nodeleft;
+                  height_diff = (height_diff < 0
+                                 ? /* noderight's height had been decremented from
+                                      h+1 to h.  The subtree's height changes from
+                                      h+3 to h+2|h+3.  */
+                                   nodeleft->balance - 1
+                                 : /* nodeleft's height had been incremented from
+                                      h+1 to h+2.  The subtree's height changes from
+                                      h+2 to h+2|h+3.  */
+                                   nodeleft->balance);
+                }
+              else
+                {
+                  /*
+                            *                     h+2
+                          /   \                 /     \
+                       h+2      h      -->    h+1     h+1
+                       / \                    / \     / \
+                      h  h+1                 h   L   R   h
+                         / \
+                        L   R
+
+                   */
+                  gl_list_node_t L = nodeleft->right = nodeleftright->left;
+                  gl_list_node_t R = node->left = nodeleftright->right;
+                  nodeleftright->left = nodeleft;
+                  nodeleftright->right = node;
+
+                  nodeleftright->parent = node->parent;
+                  if (L != NULL)
+                    L->parent = nodeleft;
+                  if (R != NULL)
+                    R->parent = node;
+                  nodeleft->parent = nodeleftright;
+                  node->parent = nodeleftright;
+
+                  nodeleft->balance = (nodeleftright->balance > 0 ? -1 : 0);
+                  node->balance = (nodeleftright->balance < 0 ? 1 : 0);
+                  nodeleftright->balance = 0;
+
+                  nodeleft->branch_size =
+                    (nodeleft->left != NULL ? nodeleft->left->branch_size : 0)
+                    + 1 + (nodeleft->right != NULL ? nodeleft->right->branch_size : 0);
+                  node->branch_size =
+                    (node->left != NULL ? node->left->branch_size : 0)
+                    + 1 + (node->right != NULL ? node->right->branch_size : 0);
+                  nodeleftright->branch_size =
+                    nodeleft->branch_size + 1 + node->branch_size;
+
+                  *nodep = nodeleftright;
+                  height_diff = (height_diff < 0
+                                 ? /* noderight's height had been decremented from
+                                      h+1 to h.  The subtree's height changes from
+                                      h+3 to h+2.  */
+                                   -1
+                                 : /* nodeleft's height had been incremented from
+                                      h+1 to h+2.  The subtree's height changes from
+                                      h+2 to h+2.  */
+                                   0);
+                }
+            }
+          else
+            {
+              /* node->balance = 2.  The subtree is heavier on the right side.
+                 Rotate from right to left:
+
+                                  *
+                                /   \
+                              h      h+2
+               */
+              gl_list_node_t noderightleft = noderight->left;
+              gl_list_node_t noderightright = noderight->right;
+              if (noderight->balance >= 0)
+                {
+                  /*
+                              *                    h+2|h+3
+                            /   \                   /    \
+                          h      h+2     -->    h+1|h+2   \
+                                 / \            /    \    |
+                             h|h+1 h+1         h   h|h+1 h+1
+                   */
+                  node->right = noderightleft;
+                  noderight->left = node;
+
+                  noderight->parent = node->parent;
+                  node->parent = noderight;
+                  if (noderightleft != NULL)
+                    noderightleft->parent = node;
+
+                  noderight->balance -= 1;
+                  node->balance = - noderight->balance;
+
+                  node->branch_size =
+                    (nodeleft != NULL ? nodeleft->branch_size : 0)
+                    + 1 + (noderightleft != NULL ? noderightleft->branch_size : 0);
+                  noderight->branch_size =
+                    node->branch_size + 1 + noderightright->branch_size;
+
+                  *nodep = noderight;
+                  height_diff = (height_diff < 0
+                                 ? /* nodeleft's height had been decremented from
+                                      h+1 to h.  The subtree's height changes from
+                                      h+3 to h+2|h+3.  */
+                                   - noderight->balance - 1
+                                 : /* noderight's height had been incremented from
+                                      h+1 to h+2.  The subtree's height changes from
+                                      h+2 to h+2|h+3.  */
+                                   - noderight->balance);
+                }
+              else
+                {
+                  /*
+                            *                    h+2
+                          /   \                /     \
+                        h      h+2    -->    h+1     h+1
+                               / \           / \     / \
+                             h+1  h         h   L   R   h
+                             / \
+                            L   R
+
+                   */
+                  gl_list_node_t L = node->right = noderightleft->left;
+                  gl_list_node_t R = noderight->left = noderightleft->right;
+                  noderightleft->left = node;
+                  noderightleft->right = noderight;
+
+                  noderightleft->parent = node->parent;
+                  if (L != NULL)
+                    L->parent = node;
+                  if (R != NULL)
+                    R->parent = noderight;
+                  node->parent = noderightleft;
+                  noderight->parent = noderightleft;
+
+                  node->balance = (noderightleft->balance > 0 ? -1 : 0);
+                  noderight->balance = (noderightleft->balance < 0 ? 1 : 0);
+                  noderightleft->balance = 0;
+
+                  node->branch_size =
+                    (node->left != NULL ? node->left->branch_size : 0)
+                    + 1 + (node->right != NULL ? node->right->branch_size : 0);
+                  noderight->branch_size =
+                    (noderight->left != NULL ? noderight->left->branch_size : 0)
+                    + 1 + (noderight->right != NULL ? noderight->right->branch_size : 0);
+                  noderightleft->branch_size =
+                    node->branch_size + 1 + noderight->branch_size;
+
+                  *nodep = noderightleft;
+                  height_diff = (height_diff < 0
+                                 ? /* nodeleft's height had been decremented from
+                                      h+1 to h.  The subtree's height changes from
+                                      h+3 to h+2.  */
+                                   -1
+                                 : /* noderight's height had been incremented from
+                                      h+1 to h+2.  The subtree's height changes from
+                                      h+2 to h+2.  */
+                                   0);
+                }
+            }
+          node = *nodep;
+        }
       else
-       {
-         /* No rotation needed.  Only propagation of the height change to the
-            next higher level.  */
-         if (height_diff < 0)
-           height_diff = (previous_balance == 0 ? 0 : -1);
-         else
-           height_diff = (node->balance == 0 ? 0 : 1);
-       }
+        {
+          /* No rotation needed.  Only propagation of the height change to the
+             next higher level.  */
+          if (height_diff < 0)
+            height_diff = (previous_balance == 0 ? 0 : -1);
+          else
+            height_diff = (node->balance == 0 ? 0 : 1);
+        }
 
       if (height_diff == 0)
-       break;
+        break;
 
       parent = node->parent;
       if (parent == NULL)
-       break;
+        break;
+    }
+}
+
+static void
+gl_tree_remove_node_from_tree (gl_list_t list, gl_list_node_t node)
+{
+  gl_list_node_t parent = node->parent;
+
+  if (node->left == NULL)
+    {
+      /* Replace node with node->right.  */
+      gl_list_node_t child = node->right;
+
+      if (child != NULL)
+        child->parent = parent;
+      if (parent == NULL)
+        list->root = child;
+      else
+        {
+          if (parent->left == node)
+            parent->left = child;
+          else /* parent->right == node */
+            parent->right = child;
+
+          /* Update branch_size fields of the parent nodes.  */
+          {
+            gl_list_node_t p;
+
+            for (p = parent; p != NULL; p = p->parent)
+              p->branch_size--;
+          }
+
+          rebalance (list, child, -1, parent);
+        }
+    }
+  else if (node->right == NULL)
+    {
+      /* It is not absolutely necessary to treat this case.  But the more
+         general case below is more complicated, hence slower.  */
+      /* Replace node with node->left.  */
+      gl_list_node_t child = node->left;
+
+      child->parent = parent;
+      if (parent == NULL)
+        list->root = child;
+      else
+        {
+          if (parent->left == node)
+            parent->left = child;
+          else /* parent->right == node */
+            parent->right = child;
+
+          /* Update branch_size fields of the parent nodes.  */
+          {
+            gl_list_node_t p;
+
+            for (p = parent; p != NULL; p = p->parent)
+              p->branch_size--;
+          }
+
+          rebalance (list, child, -1, parent);
+        }
+    }
+  else
+    {
+      /* Replace node with the rightmost element of the node->left subtree.  */
+      gl_list_node_t subst;
+      gl_list_node_t subst_parent;
+      gl_list_node_t child;
+
+      for (subst = node->left; subst->right != NULL; )
+        subst = subst->right;
+
+      subst_parent = subst->parent;
+
+      child = subst->left;
+
+      /* The case subst_parent == node is special:  If we do nothing special,
+         we get confusion about node->left, subst->left and child->parent.
+           subst_parent == node
+           <==> The 'for' loop above terminated immediately.
+           <==> subst == subst_parent->left
+                [otherwise subst == subst_parent->right]
+         In this case, we would need to first set
+           child->parent = node; node->left = child;
+         and later - when we copy subst into node's position - again
+           child->parent = subst; subst->left = child;
+         Altogether a no-op.  */
+      if (subst_parent != node)
+        {
+          if (child != NULL)
+            child->parent = subst_parent;
+          subst_parent->right = child;
+        }
+
+      /* Update branch_size fields of the parent nodes.  */
+      {
+        gl_list_node_t p;
+
+        for (p = subst_parent; p != NULL; p = p->parent)
+          p->branch_size--;
+      }
+
+      /* Copy subst into node's position.
+         (This is safer than to copy subst's value into node, keep node in
+         place, and free subst.)  */
+      if (subst_parent != node)
+        {
+          subst->left = node->left;
+          subst->left->parent = subst;
+        }
+      subst->right = node->right;
+      subst->right->parent = subst;
+      subst->balance = node->balance;
+      subst->branch_size = node->branch_size;
+      subst->parent = parent;
+      if (parent == NULL)
+        list->root = subst;
+      else if (parent->left == node)
+        parent->left = subst;
+      else /* parent->right == node */
+        parent->right = subst;
+
+      /* Rebalancing starts at child's parent, that is subst_parent -
+         except when subst_parent == node.  In this case, we need to use
+         its replacement, subst.  */
+      rebalance (list, child, -1, subst_parent != node ? subst_parent : subst);
     }
 }
 
 static gl_list_node_t
-gl_tree_add_first (gl_list_t list, const void *elt)
+gl_tree_nx_add_first (gl_list_t list, const void *elt)
 {
   /* Create new node.  */
   gl_list_node_t new_node =
-    (struct gl_list_node_impl *) xmalloc (sizeof (struct gl_list_node_impl));
+    (struct gl_list_node_impl *) malloc (sizeof (struct gl_list_node_impl));
+
+  if (new_node == NULL)
+    return NULL;
 
   new_node->left = NULL;
   new_node->right = NULL;
@@ -400,7 +567,7 @@ gl_tree_add_first (gl_list_t list, const void *elt)
       gl_list_node_t node;
 
       for (node = list->root; node->left != NULL; )
-       node = node->left;
+        node = node->left;
 
       node->left = new_node;
       new_node->parent = node;
@@ -408,22 +575,27 @@ gl_tree_add_first (gl_list_t list, const void *elt)
 
       /* Update branch_size fields of the parent nodes.  */
       {
-       gl_list_node_t p;
+        gl_list_node_t p;
 
-       for (p = node; p != NULL; p = p->parent)
-         p->branch_size++;
+        for (p = node; p != NULL; p = p->parent)
+          p->branch_size++;
       }
 
       /* Rebalance.  */
       if (node->right == NULL && node->parent != NULL)
-       rebalance (list, node, 1, node->parent);
+        rebalance (list, node, 1, node->parent);
     }
 
 #if WITH_HASHTABLE
   /* Add node to the hash table.
      Note that this is only possible _after_ the node has been added to the
      tree structure, because add_to_bucket() uses node_position().  */
-  add_to_bucket (list, new_node);
+  if (add_to_bucket (list, new_node) < 0)
+    {
+      gl_tree_remove_node_from_tree (list, new_node);
+      free (new_node);
+      return NULL;
+    }
   hash_resize_after_add (list);
 #endif
 
@@ -431,11 +603,14 @@ gl_tree_add_first (gl_list_t list, const void *elt)
 }
 
 static gl_list_node_t
-gl_tree_add_last (gl_list_t list, const void *elt)
+gl_tree_nx_add_last (gl_list_t list, const void *elt)
 {
   /* Create new node.  */
   gl_list_node_t new_node =
-    (struct gl_list_node_impl *) xmalloc (sizeof (struct gl_list_node_impl));
+    (struct gl_list_node_impl *) malloc (sizeof (struct gl_list_node_impl));
+
+  if (new_node == NULL)
+    return NULL;
 
   new_node->left = NULL;
   new_node->right = NULL;
@@ -460,7 +635,7 @@ gl_tree_add_last (gl_list_t list, const void *elt)
       gl_list_node_t node;
 
       for (node = list->root; node->right != NULL; )
-       node = node->right;
+        node = node->right;
 
       node->right = new_node;
       new_node->parent = node;
@@ -468,22 +643,27 @@ gl_tree_add_last (gl_list_t list, const void *elt)
 
       /* Update branch_size fields of the parent nodes.  */
       {
-       gl_list_node_t p;
+        gl_list_node_t p;
 
-       for (p = node; p != NULL; p = p->parent)
-         p->branch_size++;
+        for (p = node; p != NULL; p = p->parent)
+          p->branch_size++;
       }
 
       /* Rebalance.  */
       if (node->left == NULL && node->parent != NULL)
-       rebalance (list, node, 1, node->parent);
+        rebalance (list, node, 1, node->parent);
     }
 
 #if WITH_HASHTABLE
   /* Add node to the hash table.
      Note that this is only possible _after_ the node has been added to the
      tree structure, because add_to_bucket() uses node_position().  */
-  add_to_bucket (list, new_node);
+  if (add_to_bucket (list, new_node) < 0)
+    {
+      gl_tree_remove_node_from_tree (list, new_node);
+      free (new_node);
+      return NULL;
+    }
   hash_resize_after_add (list);
 #endif
 
@@ -491,13 +671,17 @@ gl_tree_add_last (gl_list_t list, const void *elt)
 }
 
 static gl_list_node_t
-gl_tree_add_before (gl_list_t list, gl_list_node_t node, const void *elt)
+gl_tree_nx_add_before (gl_list_t list, gl_list_node_t node, const void *elt)
 {
   /* Create new node.  */
-  gl_list_node_t new_node =
-    (struct gl_list_node_impl *) xmalloc (sizeof (struct gl_list_node_impl));
+  gl_list_node_t new_node;
   bool height_inc;
 
+  new_node =
+    (struct gl_list_node_impl *) malloc (sizeof (struct gl_list_node_impl));
+  if (new_node == NULL)
+    return NULL;
+
   new_node->left = NULL;
   new_node->right = NULL;
   new_node->balance = 0;
@@ -520,7 +704,7 @@ gl_tree_add_before (gl_list_t list, gl_list_node_t node, const void *elt)
   else
     {
       for (node = node->left; node->right != NULL; )
-       node = node->right;
+        node = node->right;
       node->right = new_node;
       node->balance++;
       height_inc = (node->left == NULL);
@@ -543,7 +727,12 @@ gl_tree_add_before (gl_list_t list, gl_list_node_t node, const void *elt)
   /* Add node to the hash table.
      Note that this is only possible _after_ the node has been added to the
      tree structure, because add_to_bucket() uses node_position().  */
-  add_to_bucket (list, new_node);
+  if (add_to_bucket (list, new_node) < 0)
+    {
+      gl_tree_remove_node_from_tree (list, new_node);
+      free (new_node);
+      return NULL;
+    }
   hash_resize_after_add (list);
 #endif
 
@@ -551,13 +740,17 @@ gl_tree_add_before (gl_list_t list, gl_list_node_t node, const void *elt)
 }
 
 static gl_list_node_t
-gl_tree_add_after (gl_list_t list, gl_list_node_t node, const void *elt)
+gl_tree_nx_add_after (gl_list_t list, gl_list_node_t node, const void *elt)
 {
   /* Create new node.  */
-  gl_list_node_t new_node =
-    (struct gl_list_node_impl *) xmalloc (sizeof (struct gl_list_node_impl));
+  gl_list_node_t new_node;
   bool height_inc;
 
+  new_node =
+    (struct gl_list_node_impl *) malloc (sizeof (struct gl_list_node_impl));
+  if (new_node == NULL)
+    return NULL;
+
   new_node->left = NULL;
   new_node->right = NULL;
   new_node->balance = 0;
@@ -580,7 +773,7 @@ gl_tree_add_after (gl_list_t list, gl_list_node_t node, const void *elt)
   else
     {
       for (node = node->right; node->left != NULL; )
-       node = node->left;
+        node = node->left;
       node->left = new_node;
       node->balance--;
       height_inc = (node->right == NULL);
@@ -603,148 +796,14 @@ gl_tree_add_after (gl_list_t list, gl_list_node_t node, const void *elt)
   /* Add node to the hash table.
      Note that this is only possible _after_ the node has been added to the
      tree structure, because add_to_bucket() uses node_position().  */
-  add_to_bucket (list, new_node);
+  if (add_to_bucket (list, new_node) < 0)
+    {
+      gl_tree_remove_node_from_tree (list, new_node);
+      free (new_node);
+      return NULL;
+    }
   hash_resize_after_add (list);
 #endif
 
   return new_node;
 }
-
-static bool
-gl_tree_remove_node (gl_list_t list, gl_list_node_t node)
-{
-  gl_list_node_t parent;
-
-#if WITH_HASHTABLE
-  /* Remove node from the hash table.
-     Note that this is only possible _before_ the node is removed from the
-     tree structure, because remove_from_bucket() uses node_position().  */
-  remove_from_bucket (list, node);
-#endif
-
-  parent = node->parent;
-
-  if (node->left == NULL)
-    {
-      /* Replace node with node->right.  */
-      gl_list_node_t child = node->right;
-
-      if (child != NULL)
-       child->parent = parent;
-      if (parent == NULL)
-       list->root = child;
-      else
-       {
-         if (parent->left == node)
-           parent->left = child;
-         else /* parent->right == node */
-           parent->right = child;
-
-         /* Update branch_size fields of the parent nodes.  */
-         {
-           gl_list_node_t p;
-
-           for (p = parent; p != NULL; p = p->parent)
-             p->branch_size--;
-         }
-
-         rebalance (list, child, -1, parent);
-       }
-    }
-  else if (node->right == NULL)
-    {
-      /* It is not absolutely necessary to treat this case.  But the more
-        general case below is more complicated, hence slower.  */
-      /* Replace node with node->left.  */
-      gl_list_node_t child = node->left;
-
-      child->parent = parent;
-      if (parent == NULL)
-       list->root = child;
-      else
-       {
-         if (parent->left == node)
-           parent->left = child;
-         else /* parent->right == node */
-           parent->right = child;
-
-         /* Update branch_size fields of the parent nodes.  */
-         {
-           gl_list_node_t p;
-
-           for (p = parent; p != NULL; p = p->parent)
-             p->branch_size--;
-         }
-
-         rebalance (list, child, -1, parent);
-       }
-    }
-  else
-    {
-      /* Replace node with the rightmost element of the node->left subtree.  */
-      gl_list_node_t subst;
-      gl_list_node_t subst_parent;
-      gl_list_node_t child;
-
-      for (subst = node->left; subst->right != NULL; )
-       subst = subst->right;
-
-      subst_parent = subst->parent;
-
-      child = subst->left;
-
-      /* The case subst_parent == node is special:  If we do nothing special,
-        we get confusion about node->left, subst->left and child->parent.
-          subst_parent == node
-          <==> The 'for' loop above terminated immediately.
-          <==> subst == subst_parent->left
-               [otherwise subst == subst_parent->right]
-        In this case, we would need to first set
-          child->parent = node; node->left = child;
-        and later - when we copy subst into node's position - again
-          child->parent = subst; subst->left = child;
-        Altogether a no-op.  */
-      if (subst_parent != node)
-       {
-         if (child != NULL)
-           child->parent = subst_parent;
-         subst_parent->right = child;
-       }
-
-      /* Update branch_size fields of the parent nodes.  */
-      {
-       gl_list_node_t p;
-
-       for (p = subst_parent; p != NULL; p = p->parent)
-         p->branch_size--;
-      }
-
-      /* Copy subst into node's position.
-        (This is safer than to copy subst's value into node, keep node in
-        place, and free subst.)  */
-      if (subst_parent != node)
-       {
-         subst->left = node->left;
-         subst->left->parent = subst;
-       }
-      subst->right = node->right;
-      subst->right->parent = subst;
-      subst->balance = node->balance;
-      subst->branch_size = node->branch_size;
-      subst->parent = parent;
-      if (parent == NULL)
-       list->root = subst;
-      else if (parent->left == node)
-       parent->left = subst;
-      else /* parent->right == node */
-       parent->right = subst;
-
-      /* Rebalancing starts at child's parent, that is subst_parent -
-        except when subst_parent == node.  In this case, we need to use
-        its replacement, subst.  */
-      rebalance (list, child, -1, subst_parent != node ? subst_parent : subst);
-    }
-
-  free (node);
-  return true;
-}