Dupe Bug 1.7.10

[JustZerooo]

Hello developer's,

i found a Bug, it is possible to Dupe the Runic Glass(WitherBoss-Proof).

How it works?

Build a Wither Farm with some dropper and at the end fill all with this glass. After the wither has been exploded, the glass will be duped.

Example :

[ckchessmaster]

I can also confirm this same bug. I believe it is similar to a dupe bug from earlier versions.