tavl_delete - swap whole structures, not the data pointers.

diff --git a/libraries/liblutil/tavl.c b/libraries/liblutil/tavl.c
index 923356c2ea73436f30e698d13edb0df8d97e73fc..988b7b750b86e86e81348664710d68f8470be9ef 100644 (file)
--- a/libraries/liblutil/tavl.c
+++ b/libraries/liblutil/tavl.c
@@ -220,16 +220,48 @@ tavl_delete( Avlnode **root, void* data, AVL_CMP fcmp )
 
                /* find the immediate predecessor <q> */
                q = p->avl_link[0];
-               pdir[depth] = 0;
-               pptr[depth++] = p;
+               side = depth;
+               pdir[depth++] = 0;
                while (q->avl_bits[1] == AVL_CHILD && q->avl_link[1]) {
                        pdir[depth] = 1;
                        pptr[depth++] = q;
                        q = q->avl_link[1];
                }
-               /* swap */
-               p->avl_data = q->avl_data;
-               p = q;
+               /* swap links */
+               r = p->avl_link[0];
+               p->avl_link[0] = q->avl_link[0];
+               q->avl_link[0] = r;
+
+               q->avl_link[1] = p->avl_link[1];
+               p->avl_link[1] = q;
+
+               p->avl_bits[0] = q->avl_bits[0];
+               p->avl_bits[1] = q->avl_bits[1];
+               q->avl_bits[0] = q->avl_bits[1] = AVL_CHILD;
+
+               /* fix stack positions: old parent of p points to q */
+               pptr[side] = q;
+               if ( side ) {
+                       --side;
+                       r = pptr[side];
+                       r->avl_link[pdir[side]] = q;
+               } else {
+                       *root = q;
+               }
+               /* new parent of p points to p */
+               if ( depth > 2 ) {
+                       r = pptr[depth-2];
+                       r->avl_link[1] = p;
+                       pptr[depth-1] = p;
+               } else {
+                       q->avl_link[0] = p;
+               }
+
+               /* fix right subtree: successor of p points to q */
+               r = q->avl_link[1];
+               while ( r->avl_bits[0] == AVL_CHILD && r->avl_link[0] )
+                       r = r->avl_link[0];
+               r->avl_link[0] = q;
        }
 
        /* now <p> has at most one child, get it */