Re: Search minibuffer history

[Richard Stallman]

Your code still needs a lot more comments.
Every function and every variable should have a comment,
and long functions should have an explanation of each part.

    This code prevents `isearch-message' from overwriting the minibuffer text
    with the isearch prompt.  Without this condition `isearch-message' calls
    `message' that puts the isearch prompt over the minibuffer content, so the
    user can't see the search string highlighted in the minibuffer.

I see the point of this, but if the isearch prompt is not displayed
at all, how can the user understand the search?

Perhaps the right thing to do is to make the minibuffer taller
so as to make room to display the search prompt after the minibuffer.
That would require C-level changes, but maybe not too hard.