Today I've taken another close look at branches and gerrit, and have written down my conclusions here:
http://osmocom.org/projects/cellular-infrastructure/wiki/Gerrit#Submitting-B...
In summary:
* Branch re-submission needs the workaround of tweaking the first commit. It would be nice to fix gerrit to not need this, but for the time being the effort of cosmetically changing the first commit log is acceptable.
* It *is* possible to have private branches in the gerrit repos and still be able to submit them to master, with the proper project config.
I have thus switched all our gerrit projects' configs to rebase-if-necessary with the flags as described on the wiki page. (Except for osmo-pcap, where we still disallow content merges.)
I will now go back to pushing my "private" developments to the public repository (gerrit) under the neels/ or sysmocom/ namespaces.
~Neels