Re: [PATCH/RFC] read-tree -m -u: do not overwrite or remove untracked working tree files.

Junio C Hamano wrote:

  This is an RFC patch that I consider of somewhat dubious value.
  Not the implementation quality, but the semantic change it
  implies.  Before, we could freely work in a working tree, which
  is just a scratch area to build the index, littered with
  throw-away files, knowing they would not prevent merge between
  our HEAD and other branch from happenning even if a merge needs
  to blow them away.  With this change, it is not a case anymore.
  Your merge will fail to proceed and you have to remove those
  throw-away files yourself and retry the merge.  The extent of
  the damage can be seen by the change to t1002 test this commit
  contains.  It arguably is making things much safer by refusing to
  proceed, so this might be a desirable change.  I am still
  undecided.

Perhaps the behavior should be decided by the config option, e.g.
core.preserveWorkingTree; of course that leave us with the problem what
value should be the default: the one preserving backward compatibility, or
the more safe one.

And of course --force to blow away changes anyway...

-- 
Jakub Narebski
Warsaw, Poland