When you rename a bucket item and use it, the content of the bucket disappears even when you are creative.

Step to reproduce:

• Rename a water bucket, lava bucket, powder snow bucket or milk bucket (Any name).
• Use the item in creative mode. 

Observed Results:

The item changes from a "Milk / Water / Lava / Powder Snow Bucket" to an empty bucket.

Expected Results:

The item should remain as a bucket of lava, milk, powder snow, or water as it does when the item is not renamed. (in creative mode)