BUG: The UndoManager hasUndo() method returns true when it shouldnt

I am trying to disable the undo button when there are no undo actions to do.

To do so, I am listening to 'change:changesCount' event, and using editor?.attributes?.UndoManager?.hasUndo() to set the undo button disabled state.

editor.on('change:changesCount', editor => setHasUndo(editor?.attributes?.UndoManager?.hasUndo()));

It is doing the job for me except in the below scenario:

• I am creating a new template on a blank canvas
• I drag and drop a block
• I undo

The problem here is that even though the undo now should be disabled, it is not, because editor?.attributes?.UndoManager?.hasUndo() is returning true, same as editor?.UndoManager?.hasUndo(). After doing one extra useless undo, editor?.UndoManager?.hasUndo() starts returning false.

I think the problem is that when I hover a block over the canvas, even before dropping it, we have an action added to the queue, and therefore changesCount is equal to 1 already. After dropping the block changesCount is increased to 2, while it should be 1. So there is an extra action added to the queue while it shouldn't, which is when I am dragging a block over the canvas.

To note that this doesn't happen with the second block or all the blocks after. It only happens with the first block dragged and dropped.

As a summary, when dragging and dropping the first block into the canvas, there are now 2 undo actions in the UndoManager queue, and not only 1 as expected.