How to solve the problem that KDiff adds extra blank lines when resolving merge conflicts?

How to solve the problem that KDiff adds extra blank lines when resolving merge conflicts? Changing the end line and encoding in the settings to any others does not help.

If before running git mergetool we have:

line1
line2
line3

then after starting and resolving the conflict:

line1

line2

line3

This is a bug introduced in KDiff3 version 1.8.6.

To fix it, uninstall your version of KDiff3 and install KDiff3 version 1.8.5. It should work.

Here is a link to download: https://download.kde.org/stable/kdiff3/

References:

• https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=256606
• https://invent.kde.org/sdk/kdiff3/-/issues/25#register-pane

EDIT: This bug is fixed in 1.9.5 as per https://bugs.kde.org/show_bug.cgi?id=442199