Jabref adds a comma after the last line of bibentry, before the closing brace

I just wonder: A comma was forbidden in this situation:
author= {someone},
title = {something},
year= {someyear}
As long as I have been using Bibtex a comma before the closing brace was forbidden. However, inspecting the bib-file jabref produces I saw this comma. Is this intentional? Is the comma causing any longer any errors? Would be nice to know.

We are not aware of any problems resulting from the comma before the last closing bracket (and there is sadly no “bibtex standard”). The decision for always writing the comma was made to facility the use of code version systems like git and svn. If you add another field which is written after the previously last field, then only this one line is changed and not also the one before (as it would be the case if JabRef needs to add a comma).

I looked for errors which would make pdflatex stop and I saw this. When I had last added entries to bib file manually, there was to be no comma. But this has obviously changed. I found the error anyhow. This was not at the origin of my faulty compilation.