Simplify put code and make free leave table in clean state.

src/ht.c

@@ -35,40 +35,36 @@ void ht_init(ht* ht) {
 void ht_free(ht* ht) {
   int index = 0;
   for (; index < LIBDS_HT_SIZE; index++) {
-    ht_node* head = ht->data[index];
-    while (head) {
-      ht_node* to_delete = head;
-      head = head->next;
+    while (ht->data[index]) {
+      ht_node* to_delete = ht->data[index];
+      ht->data[index] = to_delete->next;
       ht->free_func(to_delete->key);
       free(to_delete);
     }
   }
+  ht->cmp_func = NULL;
+  ht->copy_func = NULL;
+  ht->free_func = NULL;
+  ht->hash_func = NULL;
 }
 
 libds_result ht_put(ht* ht, void* key, void* data) {
   libds_result result = LIBDS_SUCCESS;
   ht_node* new_node = NULL;
+  void* new_key = NULL;
   unsigned long key_int = ht->hash_func(key) % LIBDS_HT_SIZE;
 
   new_node = malloc(sizeof(*new_node));
-  if (new_node) {
+  new_key = ht->copy_func(key);
+  if (new_node && new_key) {
     new_node->data = data;
-    new_node->key = ht->copy_func(key);
-    if (new_node->key == NULL) {
-      result = LIBDS_MALLOC;
-    }
-  } else {
-    result = LIBDS_MALLOC;
-  }
-
-  if (result != LIBDS_SUCCESS) {
-    if (new_node) {
-      free(new_node);
-      new_node = NULL;
-    }
-  } else {
+    new_node->key = new_key;
     new_node->next = ht->data[key_int];
     ht->data[key_int] = new_node;
+  } else {
+    free(new_node);
+    free(new_key);
+    result = LIBDS_MALLOC;
   }
 
   return result;