I see, thanks for the explanation. That's still unsatisfactory to me. I think an ideal incremental word search would just start over from the current point each time a new character is typed (that's what most users would expect). Then any non-insertion command would make the user "commit" to the particular search and the incremental search proper would begin. Is that compatible with the current design of isearch? 

Best,
Antoine 

On 29 Jan 2017 01:50, "Juri Linkov" <juri@linkov.net> wrote:
merge 22589 25562
thanks

> emacs -Q
> M-<
> M-s w
> it
>
> see that the "it" of "visit" is matched, and should not be. Subsequent
> C-s fix this.

Thanks for the report.  Please see the rationale for this behavior in
https://debbugs.gnu.org/22589

Do you think the proposed change suits your case?