What need to be reset when calling DMSetType?
DMSetType
https://gitlab.com/petsc/petsc/blob/master/src/dm/interface/dm.c#L3536 zeroes only the pointers for the DMOps
, but does not touch any other entry of the huge _p_DM
struct (neither setup
nor setupcalled
, which at least should be reset to PETSC_FALSE
). I think we should decide what need to be reset at this point, and what instead can be kept inside the DM