bug#7700: 24.0.50; C-y binding withing Isearch mode

[Stefan Monnier <monnier@iro.umontreal.ca>]

>>>> I suggest instead that any standard forward movement command while in
>>>> isearch forward mode should select the text to grab WITHOUT any
>>>> prefix key.
>> That might be a good choice, but:
>> - we lack experimental evidence for that.
>> - it would probably be too big a change to have that as a default behavior.
> IMHO, that proposal would make text grabbing in Isearch (a) More
> powerful (you could use every movement command to grab text), and (b)
> easier/simpler (you already know the movement commands).

Compared to the use of a prefix, there is an important difference: the
prefix tells isearch that the next command is a movement command, so it
can be used with *any* command (and can lead to surprises if the command
is not a movement command), whereas in the absence of a prefix, isearch
would need to know which commands are "movement commands", and this
knowledge would always tend to be partial, so it will fail with
some commands.

> The only drawback I can see is to give up the possibility of exit
> Isearch mode with a movement command, but IMO, this loss is
> insignificant compared with the benefits.

Depends significantly on your usage pattern.  I know such a change to
the default behavior would cause screams and never ending arguments.
So we'd fist have to see this change in action for a while to
demonstrate that the benefit is worth the cost of transitioning.


        Stefan