Re: [WIP/PATCH] Teach fast-import to print the id of each imported commit

> For the svn importer, it would be useful to have a map from
> subversion revision numbers to git commits.  This is particularly
> relevant because the subversion api sometimes represents as "copy
> this directory from this revision", and the importer needs to be
> able to access the corresponding trees.  So (optionally) print
> each commit id when the corresponding object is written.
> 
> Unfortunately when each commit object is written, it is not yet
> accessible to the caller.  The corresponding pack index
> and header are not written until the next checkpoint finishes.
> 
> Should fast-import accept lines of the form
> 
>  M 100644 <commit id>:<path> <path>
> 
> and
> 
>  M 040000 <commit id>:<path> <path>
> 
> to allow the caller to use commits before they are accessible
> through the git object database?
> 
> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
> but definitely not ready for inclusion