Size of popup changed in some cases when text is often completly removed and re-added

[rugk]

When you delete all text and only input one letter, delete it again, input again, etc. it often happens that the popup window is re-sized 5px or so for each new "showing" of that window. After some "cycles" it seems to end/to be limited though.
The reason seems to be the placeholder, which is shown and hidden by the JS if everything is removed there.

Actually the underlying problem is, that the whole thing (textarea) jumps/resizes itself when it is hidden. Although the element has it's width and height clearly set (otherwise it would also collapse when no element is inside of it.). Here is a GIF where I just hide it (no other change!):

It does not matter whether I hide the SVG placeholder or the Canvas, it's both the same.

It even happens, when only the alt text is displayed:

It is reproducible in Firefox 60 and without JS:

Maybe it is also a Firefox bug?

[rugk]

Should be fixed in 1.1/current master.