Re: suggestion in query-replace is messed up after cancelation

[Chong Yidong]

>> + (defvar query-replace-defaults nil
>> +   "Default values of FROM-STRING and TO-STRING for `query-replace'.
>> + This is a cons cell (FROM-STRING . TO-STRING), or nil if there is
>> + no default value.")
>
> What about having a list of cons cells (FROM-STRING . TO-STRING)
> of all previous replacements and using new keys (e.g. M-P and M-N)
> to access previous/next replacements pairs from the replacement pair
> history?

That is not so straightforward to implement since we can't use a list
of cons cells as a history list for read-from-minibuffer.

>> !       (if (and (zerop (length from)) query-replace-defaults)
>>        (progn
>>          (set query-replace-from-history-variable
>>               (cdr (symbol-value query-replace-from-history-variable)))
>
> We don't need this `set' anymore.

We do, at least in this patch, since read-from-minibuffer
automatically updates the history list (which is still given by
query-replace-from-history-variable).