Bug in filter Morphological

Win7 - latest download

I open a new file - background transparency

I fill all image with a colour, then I paint a simple O by hand in black

After that I go to Filter menu and I choose Morphological - Erosion (minimum)

then I need to UNDO - so in the menu Edit I choose and click on UNDO

nothing happens

So I click on that menu 3 or 4 times and nothing happens

but if I go away - the filter list desappears from my left too - , selecting a pencil, then the image is void, blank, as it was when opened as a new file...

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The bug is the same when you use a filter of your choice, if you click on OK or cancel, you can do your undo simply and in a viewable mode. Otherwise your undo is working but in a hiding mode and you don't know what happening. Maybe the better way is to use the UNDO and to render the exact image in that moment.