Thanks for the merge.
I found a more general solution, as there could be the posibility to have the author as "select" or "radio box" input in the form, where the fix breaks.
But I think in most of the cases the author is a preset input, if used with "restrict edit = 1", so the merged fix should be fine.
https://bitbucket.org/merrx/elog/commits/7aacfbcac43b1192e5271fa7b2c80f4825c94d23

Today we ran into this issue again, but this time the curpit was encoding...
The author name in the password file was differently encoded as the author name from the xhr request.
For this instance there was a umlaut in the name.

I haven't got a good solution for this at the moment.
The workaround is to check the encording in the password file and make it matching.
But as for automated logins / user generation e.g. via LDAP (in our case) one should be aware of this issue.