contributing

[sliptonic]

add cla

[jedbrown]

Note that it's widely believed Apache-2.0 is incompatible with GPL-2.0/LGPLv2.1. There are two common theories for why this is:

1. The patent indemnification clause in Apache-2.0 section 3 represents a "further restriction" on distribution of the (L)GPL software.
2. The warranty clause in Apache-2.0 section 9 represents a "further restriction" on distribution of the (L)GPL software.

Under the former theory (which is the one cited by the FSF), the inbound license granted by the Apache-style CLA does not grant you permission to distribute under LGPL-2.1-or-later (the inbound license has section 3 restrictions). I see you have a DCO already in this commit, and would recommend sticking with that (which clarifies provenance and grants inbound=outbound) instead of modifying the CLA to grant the permissions you need to grant LGPL-2.1-or-later outbound.

If it is deliberate to grant Ondsel a permissive inbound license, this creates an asymmetry in that Ondsel could make this package proprietary, but no others in the community could do so. (This makes the community nervous about substantial contributions, in the sense that various companies in the broader open source world have exploited such asymmetry even when founders have pledged never to do such a thing.) A symmetric alternative is to license OndselSolver as Apache-2.0 OR MIT (inbound=outbound per DCO), which ensures all the necessary compatibility with FreeCAD and other uses.