In Creative Mode, the default creative mode items always reappear in your inventory when you do not have any items and exit and enter the world
Steps to Reproduce
1.In Creative Mode, remove or clear your inventory, then exit the world and re-enter. As you can see the items in the default creative mode (Wood, saplings, Torches, etc.) appear in your inventory
NOTE: This error will work only if the "Default Game Mode" option in the world menu is in creative mode