The traditional expectation for contributions to a free software project are inbound=outbound [1] [2]. That is, if the project is under license X, contributions are made under license X.Does this apply to a project released under any/all of the following licenses with no additional CLA?LGPL v2-onlyGPL v2-onlyLGPL v2-or-laterGPL v2-or-laterLGPL v3-onlyGPL v3-onlyAGPL v3-onlyLGPL v3-or-laterGPL v3-or-laterAGPL v3-or-laterI am not concerned with compatibility beyond that, just that in each case that contributions are by default the same GPL-variant as the original project.
Does inbound=outbound apply to GPL-family without a CLA?
gpl;lgpl;agpl 3.0;collaboration;contributor agreements
Yes, submissions to a GPL codebase remain under the same GPL variant. This is specifically because of the copyleft mechanism. For example, from section 10 of the GPLv3 license text:Each time you convey a covered work, the recipient automatically receives a license from the original licensors, to run, modify and propagate that work, subject to this License.This applies to all listed variants of the GPL (version 2/3, only/or-later clause, A/L/GPL variant). Specific modifications to the license terms are sometimes allowed (for example, by the or later clause), but by default the terms remain the same.