Test case based on editing https://de.wikipedia.org/wiki/Krupp_%28Familie%29#Familienstammbaum
A huge block of newlines is shown in edit mode when indention reduces rapidly, i.e. from 7 : to 2 :
The normal instinct of a Wikipedia is to remove these newlines.
Version: unspecified
Severity: normal
URL: https://test.wikipedia.org/wiki/User:Raymond/lists