bug#46469: 27.1; `isearch-del-char' should move point further back

[Juri Linkov]

> Suppose my buffer contains the text "x1yx2" right after point, and that
> `isearch-del-char' is bound to DEL in Isearch mode.  If I type
>
>    C-s y DEL x1
>
> then I would expect the search to succeed: the cursor would first go
> after "y", then return to the starting point of search after pressing
> DEL – this is how `isearch-delete-char' behaves, anyway.
>
> Instead, the cursor remains after "y" after pressing DEL, and the search
> fails with the cursor after the second "x".  I have attached a patch to
> fix this.

Sorry, the reason for the current behavior is explained in the comments.
Anyway isearch-fallback in your patch does nothing.  Maybe you intended
to use isearch-pop-state, but this what isearch-delete-char already does.

> I have also attached a second trivial patch for an unrelated, very tiny
> bug.

Thanks, this fix is now pushed to master.