Re: [PATCHv3 3/3] submodule absorbing: fix worktree/gitdir pointers recursively for non-moves

> Consider having a submodule 'sub' and a nested submodule at 'sub/nested'.
> When nested is already absorbed into sub, but sub is not absorbed into
> its superproject, then we need to fixup the gitfile and core.worktree
> setting for 'nested' when absorbing 'sub', but we do not need to move
> its git dir around.
> 
> Previously 'nested's gitfile contained "gitdir: ../.git/modules/nested";
> it has to be corrected to "gitdir: ../../.git/modules/sub1/modules/nested".
> 
> An alternative I considered to do this work lazily, i.e. when resolving
> "../.git/modules/nested", we would notice the ".git" being a gitfile
> linking to another path.  That seemed to be robuster by design, but harder
> to get the implementation right.  Maybe we have to do that anyway once we
> try to have submodules and worktrees working nicely together, but for now
> just produce 'correct' (i.e. direct) pointers.
> 
> Signed-off-by: Stefan Beller <sbeller@google.com>