NPE with clipboard patterns/brushes when player clipboard changed after pattern/brush creation

Server Implementation

Paper

Server Version

1.18.2

Describe the bug

When you select an area, perform //copy and go to assign it to a brush (eg. /br clipboard -ao) it will work perfectly. However, let's say that you messed up the point where you copied from and went back to perform //copy once more. The blocks copy but when you go to use the brush it will not work and will spam console with hundreds of different errors repeating it and then tens of thousands of NullPointerExceptions over period of ~ 5 seconds.

To Reproduce

//pos1 & //pos2
//copy
//gmask 0
/br clipboard -ao
//copy
(Then use the brush again.)

Expected behaviour

I expected the copy and work the brush properly.

Screenshots / Videos

https://youtu.be/SR4rlzdeo4w

Error log (if applicable)

https://gist.github.com/KalebDev1/604562582992900f1e83af55ce925f05

Fawe Debugpaste

https://athion.net/ISPaster/paste/view/5b8f76a1f98e44e28166decf6a91efa9

Fawe Version

FastAsyncWorldEdit-Bukkit-2.4.1-SNAPSHOT-239

Checklist

• I have included a Fawe debugpaste.
• I am using the newest build from https://ci.athion.net/job/FastAsyncWorldEdit/ and the issue still persists.

Anything else?

No response

Start by reproducing the reported sequence with //copy, /br clipboard -ao, and a second //copy, then inspect the linked error log and FAWE debugpaste for the NullPointerException source. Done means the clipboard brush continues working after the player's clipboard changes and the console no longer receives repeated exceptions.