Binary search tree two similar functions producing garbage - c++

Question

I've got this call
productTree.displayNode(productTree.newsearchTree(search, productTree.Root()));
Calling these functions
void Tree::displayNode(Node* node) {
if (node != NULL) {
cout << node->productdata << endl;
}
}
Node* Tree::newsearchTree(string search, Node* node) {
if (node != NULL) {
newsearchTree(search, node->left);
if (search == node->productdata.getName()) {
return node;
}
newsearchTree(search, node->right);
}
}
Node* Root() { return root; };
Which produces a garbage output when trying to display the returned node.
And yet, I can traverse my tree and display it easily this way:
This call:
productTree.Inorder(productTree.Root());
Functions:
void Tree::Inorder(Node* node) {
if (node != NULL) {
Inorder(node->left);
displayNode(node);
Inorder(node->right);
}
}
And where I am confused is how are they different?
Edit: Thank you for your help, I modified the code as below and it works fine now:
Node* Tree::newsearchTree(string search, Node* node) {
if (node != NULL) {
newsearchTree(search, node->left);
if (search == node->productdata.getName()) {
return node;
}
newsearchTree(search, node->right);
}
return NULL;
}
void Tree::displayNode(Node* node) {
if (node != NULL) {
cout << node->productdata << endl;
}
else if (node == NULL) {
cout << "Product not found" << endl;
}
}
Yep, that's still broken. This finally fixed it I believe:
Node* Tree::newsearchTree(string search, Node* node) {
if (node != NULL) {
if (search == node->key) {
return node;
}
if (search < node->key) {
return newsearchTree(search, node->left);
}
else {
return newsearchTree(search, node->right);
}
}
else return NULL;
}

Answer 1

Let me add comments inline to make it clear what your Tree::newsearchTree does.
Node* Tree::newsearchTree(string search, Node* node) {
if (node != NULL) {
newsearchTree(search, node->left); // burn CPU but leaves no side effect
if (search == node->productdata.getName()) {
return node; // return node only if the root node equals 'search'
}
newsearchTree(search, node->right); // burn CPU without side effect
}
// In majority of the cases (root node != 'search'): return nothing.
}
Because typically newsearchTree() returns nothing, when you call productTree.displayNode(productTree.newsearchTree(...)) you basically print garbage.