Bad Regression in 5.43 and 5.44

[Dominik Haumann]

Hi,

my fix for bug https://bugs.kde.org/show_bug.cgi?id=306745 with review
https://phabricator.kde.org/D10054 unfortunately introduced a
regression:

https://bugs.kde.org/show_bug.cgi?id=391838

Now, the view does not scroll down anymore at all when navigating
downwards in a dynamically wrapped line.

I tried to fix the first bug above already years ago, and apparently
my final fix recently made things much worse. In other words: Could
someone with fresh eyes look on this?

If nothing happens here within the next week, I will revert my other
fix, remove or disable the unit test, and we are back to the old also
broken behavior.

Thanks
Dominik