Consider the following hypothetical situation.
A project was open sourced. There were a number of external contributions but not too many. Imagine, the owner wants to change its license. Is it possible to do it like this:
- Ask author of patches for a license change
- Remove all patches by contributors who don't want a relicensing
- Rewrite missing part
- Change a license
Will it be legal? Are patches applied after the first non relicenseable contribution considered a derivative work if there were no functional or code copying?