* doc/emacs/search.texi (Query Replace): Mention new key 'd'.
* lisp/replace.el (query-replace-help): Mention the key 'd'.
(query-replace-map): Bind the key 'd' to 'diff'.
(perform-replace): When 'def' is equal to 'diff',
call 'multi-file-replace-as-diff' to show the diff buffer
with replacements (bug#79761).
f4d353f9c9