in reply to Jörn Franke

@jornfranke
We have support for manual merges. The detection is still not perfect, but works in most cases, and you can always provide the commit id that merged a PR instead of pressing the merge button if it failed for some reason.

The option is "Enable autodetect manual merge (Note: In some special cases, misjudgments can occur)" in the Pull requests repo settings.
@bagder