bug#1948: confusion and bug in dabbrev.el

[Alan J Third]

Alan J Third <alan@idiocy.org> writes:

> Type:
>
> one  tt
> one  ww
>
> Then in the next line I have to type:
>
> one 
>    ^- space
>
> and M-/ (dabbrev-expand) completes it to:
>
> one ww
>
> Then if I hit M-/ again, point jumps up to the line above and replaces
> "ww". Subsequent M-/'s continue to fiddle with the same line.

I got this slightly wrong. The full set of commands is:

Type:

one  tt
one  ww
on M-/ SPC M-/ M-/

I've written a test, but I'm not sure what to do with it:

(ert-deftest dabbrev-expand-test ()
  "Test for bug#1948.
When DABBREV-ELIMINATE-NEWLINES is non-nil (the default),
repeated calls to DABBREV-EXPAND can result in the source of
first expansion being replaced rather than the destination."
  (with-temp-buffer
   (insert "ab  x\na\nab  y")
   (goto-char 8)
   (save-window-excursion
     (set-window-buffer nil (current-buffer))
     ;; M-/ SPC M-/ M-/
     (execute-kbd-macro "\257 \257\257"))
   (should (string= (buffer-string) "ab  x\nab y\nab  y"))))

I haven't signed the copyright assignment stuff.
-- 
Alan Third