(defun choose-completion-string (choice &optional buffer base-size)
"Switch to BUFFER and insert the completion choice CHOICE.
BASE-SIZE, if non-nil, says how many characters of BUFFER's text
-to keep. If it is nil, use choose-completion-delete-max-match instead."
+to keep. If it is nil, we call `choose-completion-delete-max-match'
+to decide what to delete."
;; If BUFFER is the minibuffer, exit the minibuffer
;; unless it is reading a file name and CHOICE is a directory,