bug#4117: 23.1; isearch + isearch-allow-scroll loses shift

[Juri Linkov]

>   When `isearch-allow-scroll' is turned on, then exiting isearch with
>   a movement command loses its "shift" status.  To see this, use
>   isearch and look for some string, then hit C-S-right a few times and
>   you will see that the first one does not starts a selection.

When `isearch-allow-scroll' is non-nil, then `isearch-other-meta-char'
calls `isearch-reread-key-sequence-naturally', but `read-key-sequence'
in the latter function removes the shift modifier and sets
`this-command-keys-shift-translated' to t.

This is just an analysis.  I currently don't know what is the right way
to fix this.  Maybe simply add the shift modifier back to the key when
`this-command-keys-shift-translated' to t after `read-key-sequence'.

-- 
Juri Linkov
http://www.jurta.org/emacs/