Replacing text of nodes in Firefox does not work

[tim-krieger]

If I completely delete the text of a root node or node in Firefox (77.0.1, Linux 64bit), I cannot enter a new name.

[tim-krieger]

Perhaps the issue is related to #80.

[tim-krieger]

Firefox adds <div> if a user presses enter:
https://stackoverflow.com/questions/425274/prevent-line-paragraph-breaks-in-contenteditable#428139

[tim-krieger]

This seems to be caused by a bug in Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=1513303

[tim-krieger]

Additional info:

1. Delete the content of the root node.
2. Type a name for the root node.
3. The text is hidden and only appears after clicking the Mindmapp tab.