Previously only Functions were passed to the TransferManagers by the firedrake multigrid code. Now sometimes Cofunctions are passed. However, we used ufl.domain.extract_unique_domain in the ManifoldTransferManager to get the mesh, which doesn't work with a Cofunction.
This PR changes the ManifoldTransferManager to just grab the mesh off the function_space instead, which works for both Function and Cofunction. It also tidies up the code in ManifoldTransferManager a bit.
Previously only
Functionswere passed to theTransferManagersby the firedrake multigrid code. Now sometimesCofunctionsare passed. However, we usedufl.domain.extract_unique_domainin theManifoldTransferManagerto get the mesh, which doesn't work with aCofunction.This PR changes the
ManifoldTransferManagerto just grab themeshoff thefunction_spaceinstead, which works for bothFunctionandCofunction. It also tidies up the code inManifoldTransferManagera bit.