Add cJSON_DetachItemViaPointer

cJSON.c

@@ -1814,6 +1814,36 @@ CJSON_PUBLIC(void) cJSON_AddItemReferenceToObject(cJSON *object, const char *str
     cJSON_AddItemToObject(object, string, create_reference(item, &global_hooks));
 }
 
+CJSON_PUBLIC(cJSON *) cJSON_DetachItemViaPointer(cJSON *parent, cJSON * const item)
+{
+    if ((parent == NULL) || (item == NULL))
+    {
+        return NULL;
+    }
+
+    if (item->prev != NULL)
+    {
+        /* not the first element */
+        item->prev->next = item->next;
+    }
+    if (item->next != NULL)
+    {
+        /* not the last element */
+        item->next->prev = item->prev;
+    }
+
+    if (item == parent->child)
+    {
+        /* first element */
+        parent->child = item->next;
+    }
+    /* make sure the detached item doesn't point anywhere anymore */
+    item->prev = NULL;
+    item->next = NULL;
+
+    return item;
+}
+
 static cJSON *DetachItemFromArray(cJSON *array, size_t which)
 {
     cJSON *c = array->child;