gerrit: pull, change, commit --amend and submit after many changes in master since first submit to gerrit

[Winfried Donkers <winfried.libreoffice@xxxxxxxxx>]

Hi,

I have submitted a patch to gerrit weeks ago and I now want to change 
some of it (the patch in gerrit is still active).

When pulling the patch from gerrit, I get a merge commit.
I can change my patch, but how do I update the patch (I normally use 
'git commit path_or_-a --amend' for this, but the patch is not the 
latest commit)?

Winfried