Closing widgets leaves a small blank line

[e-dorigatti]

This becomes noticeable in a loop. For example, run this in a notebook:

from ipywidgets import HTML
for i in range(5):
    c = HTML(f'it. <b>{i}</b>')
    display(c)
    if i < 4:
        c.close()

Even though the widgets are closed, the container is still there, with non-zero height:

This is the HTML:

<!-- first four empty containers are like this -->
<div class="p-Widget p-Panel jp-OutputArea-child">
  <div class="p-Widget jp-OutputPrompt jp-OutputArea-prompt"></div>
  <div class="p-Widget p-Panel jupyter-widgets jp-OutputArea-output p-mod-hidden"></div>
</div>

<!-- last container with content --->
<div class="p-Widget p-Panel jp-OutputArea-child">
  <div class="p-Widget jp-OutputPrompt jp-OutputArea-prompt"></div>
  <div class="p-Widget p-Panel jupyter-widgets jp-OutputArea-output">
    <div class="p-Widget jupyter-widgets widget-inline-hbox widget-html">
      <label class="widget-label" style="display: none;" title=""></label>
      <div class="widget-html-content">it. <b>4</b></div>
    </div>
  </div>
</div>

[e-dorigatti]

Guess this is a duplicate of #1845. Sorry.

[jasongrout]

Guess this is a duplicate of #1845. Sorry.

Yes. It's a difficult problem because we're working around things in the notebook paradigm.