bug#19829: 25.0.50; query-replace in rectangle regions do not honor boundaries

[Juri Linkov]

>> When selecting a region with C-x SPC, then M-% will suggest
>> replacement in the non-rectangular region.  I expected the
>> replacements to be suggested within the rectangular region.
>
> It would be very easy to support the rectangular region replacements
> the same way as such replacements are already supported in WDired
> where replacements are restricted to the vertical column of filenames.
>
> But the problem is that I don't see how the information about
> column positions of the selected rectangular region would be
> supplied to query-replace by region-beginning and region-end.

I wonder how do other commands that accept region-beginning/end
process the rectangular region?