bug#6917: forward-comment moves also if nil

[Glenn Morris]

tags 6917 notabug wontfix
stop

> if `(forward-comment 1)' is called with some empty lines
> ahead followed by non-commented code, it returns nil
> but travels buffer like
> `(skip-chars-forward " \n")' would do.

It is behaving as documented:

  Stop scanning if we find something other than a comment or whitespace.
  Set point to where scanning stops.
  
  If COUNT comments are found as expected, with nothing except
  whitespace between them, return t; otherwise return nil.