Hey, I'm trying to write a program using binary search trees. Everything seems to work up to a certain point, which (as far as I know) shouldn't produce an error. It segmentation faults while it's executing the code below.

Not all of this code was written by me. I just had to modify it.Code:static BstreeNode* tree_insert_helper(Bstree *tree, BstreeNode *current_node, int key, void *value) { if (current_node == NULL) { // create a new leaf node current_node = (BstreeNode *)malloc(sizeof(BstreeNode)); current_node->left_child = NULL; current_node->right_child = NULL; current_node->key = key; current_node->value = value; printf("Beginning linking the root node\n"); printf("%d\n", current_node->key); // If making the root node if(tree->root->key == current_node->key) //!!! Has some problem with accessing tree's fields! This is where it seg faults. { printf("Linking the root node\n"); current_node->next = tree->sentinelNode; current_node->prev = tree->sentinelNode; tree->sentinelNode->next = current_node; tree->sentinelNode->prev = current_node; } } else { int compare_result = key - current_node->key; if (compare_result < 0) { current_node->left_child = tree_insert_helper(tree, current_node->left_child, key, value); if(key == current_node->left_child->key) { current_node->left_child->next = current_node; current_node->left_child->prev = current_node->prev; current_node->prev = current_node->left_child; current_node->left_child->prev->next = current_node->left_child; } } else if (compare_result > 0) { current_node->right_child = tree_insert_helper(tree, current_node->right_child, key, value); if(key == current_node->right_child->key) { current_node->right_child->prev = current_node; current_node->right_child->next = current_node->next; current_node->next = current_node->right_child; current_node->right_child->next->prev = current_node->right_child; } } // else set key to new value else current_node->value = value; } return current_node; } void bstree_insert(void *binary_tree, int key, void *value) { Bstree *tree = (Bstree *)binary_tree; tree->root = tree_insert_helper(tree, tree->root, key, value); }

The definitions of Bstree and BstreeNode are as follows:

Code:typedef struct bstreenode { int key; void *value; struct bstreenode *left_child; struct bstreenode *right_child; struct bstreenode *next; struct bstreenode *prev; } BstreeNode; typedef struct { BstreeNode *root; BstreeNode *sentinelNode; } Bstree;

What could be causing a seg fault in this code?