files that are concerned by the current operation (using relative names);
`log-edit-diff-function' -- function taking no arguments that
displays a diff of the files concerned by the current operation.
- `vc-log-fileset' -- the VC fileset to be committed (if any).
+ `vc-log-fileset' -- list of files to be committed, if any
+ (not a true VC fileset structure as returned by
+ `vc-deduce-fileset', but only the second element).
If BUFFER is non-nil, `log-edit' will switch to that buffer, use it
to edit the log message and go back to the current buffer when