Это похоже на то, что вы хотите:
C-x C-o runs the command delete-blank-lines, which is an interactive
compiled Lisp function in `simple.el'.
It is bound to C-x C-o.
(delete-blank-lines)
On blank line, delete all surrounding blank lines, leaving just one.
On isolated blank line, delete that one.
On nonblank line, delete any immediately following blank lines.