* lisp/simple.el (kill-line): The effect of show-trailing-whitespace is
important lines with *no* nonblanks (Bug #16654).
\\[move-beginning-of-line] \\[kill-line] \\[kill-line].
If `show-trailing-whitespace' is non-nil, this command will just
-kill the rest of the current line, even if there are only
-nonblanks there.
+kill the rest of the current line, even if there are no nonblanks
+there.
If option `kill-whole-line' is non-nil, then this command kills the whole line
including its terminating newline, when used at the beginning of a line