Fix issues that would lead to seg fault on the online method

1 files changed, 8 insertions, 3 deletions

diff --git a/src/dfs.c b/src/dfs.c
index b0bda53..12f4ee2 100644
--- a/src/dfs.c
+++ b/src/dfs.c
@@ -92,11 +92,12 @@ struct online_return dfs_online(struct data * data, struct front_item * front, s
       front_last->next = new_front_item(tree->values.p, tree->values.w, front_last, NULL);
       front_last = front_last->next;
       
+      /* Adjust prev and next */
+      if(tree->prev != NULL) tree->prev->next = tree->next;
+      if(tree->next != NULL) tree->next->prev = tree->prev;
+      
       struct tree_item * old = tree;
       tree = tree->next;
-      if(tree != NULL) {
-        tree->prev = old->prev;
-      }
       free(old);
 
       change++;
@@ -125,6 +126,10 @@ struct online_return dfs_online(struct data * data, struct front_item * front, s
     /* Update left next */
     left->next = right;
 
+    /* Adjust prev and next */
+    if(tree->prev != NULL) tree->prev->next = left;
+    if(tree->next != NULL) tree->next->prev = right;
+
     /* Update tree to left node and free old node */
     struct tree_item * old = tree;
     tree = left;