bug#11381: 23.3; isearch-search-and-update issue?

[Stefan Monnier <monnier@IRO.UMontreal.CA>]

>> > Comparing two functions can be avoided by using properties
>> > on function symbols like in the patch below.
>> It's not perfect, but yes, it's much better.
> Actually, I very much dislike this "feature" of putting properties on
> function symbols, or at least the way we use it.

Agreed, hence the "not perfect".

> I say, either we start documenting these properties in the doc strings
> and in the manual, or we should deprecate and discourage the practice
> of using them.

For delsel, I think the answer is to not use properties (which is why
I insisted we use another mechanism for the shift-select and
delete-active-region thingies).

For the case at hand, it's more difficult to fold the functionality
directly into the function (that would make us turn those functions
into object-like functions, along the lines of what we do for
completion tables).

And, I agree that the docstring of isearch-search-fun-function should
then clearly document what the `isearch-message-prefix' means.


        Stefan