Inventory items lost using anvil GUI

[Erlebsyk]

Description
I've noticed a bug where inventory items are permanently lost if the anvil GUI is not used correctly. If any item is shift-cliked while using the anvil GUI, the item is inserted into the second slot and can no longer be returned to the player. Example video.

Impact
This is not an issue with normal use, however it can be very unfortunate if valuable items are lost if someone accidentally shift-clicks one of their items.

Steps to reproduce
Open GUI, add new waypoint or folder to open anvil GUI, then shift-click an item within the inventory to insert it into the second anvil slot. It is also possible to insert an item into the second anvil slot by repeatedly left-clicking it with a selected item. The inserted item is then lost.

System
Java 1.8
Minecraft version 1.15.2
Paper latest version (for now anyway): Paper-121 (API version 1.15.2-R0.1-SNAPSHOT)
Plugin version: 2.6.1

Error logs
No logs or errors displayed in console.

[Sytm]

You should report that bug to WesJD/AnvilGUI, as it is his library I am using for the anvil GUI, so sorry I cannot help you with that.

But thanks for contributing to properly formatted issues!

[Erlebsyk]

Thanks for the quick reply. This bug just got fixed in WesJD/AnvilGUI #62. See the issue referenced above for more details, where WesJD replied: "I appreciate the detailed issue. This issue will be fixed in #62. Please remind the plugin developer to update the plugin once I merge that PR in a few minutes.".