Adding label produces GraphQL error: Unexpected HTTP status 500

Issue Summary

Hitting Add button on label dialogue without any text or without clicking create label from drop-down produces HTTP 500 error.

Environment

New editor.

Steps to Reproduce

1. Open any page which is using the new Confluence editing experience.
2. Click to open labels dialogue (shortcut is L key)
3. Enter a label, or leave the field empty, and click Add button but do NOT select a label from the drop-down that appears or select to create a new label. The error occurs when you simply click add without confirming the label from the drop-down.

Expected Results

The empty label field is validated and the message is shown or nothing happens

Actual Results

HTTP 500 GraphQL error pops up

GraphQL error: Unexpected HTTP status 500

Notes

label_bug.mov

^{Recording #6.mp4}

Workaround

Select create dialogue and ensure text has been entered and click Add.