gnus-summary-limit-to-author, can we change it?

[Eric Abrahamsen <eric@ericabrahamsen.net>]

Commit c79df675b50e367e228dde5f417fca33e60814d8 inserts the "from"
address of the message under point as the default address to use when
filtering with `gnus-summary-limit-to-author'.

I use this function all the time, and so far this behavior has not once
been what I want -- having to delete the default address adds a
cumbersome step to what was once my speediest method of finding recent
messages.

More user-friendly might be to use the "From" address of the message
under point as a default only if a blank string is given at the prompt.
So you hit `/ a', and you see:

"Limit to author (regexp, default from@under-point.com): "

Hit enter directly to limit to "from@under-point.com", or type a string
and enter to limit to that.

I'd be happy to submit a patch to this effect if the above sounds
acceptable. Might as well do it for all "limit-to" functions that
operate on a specific header too, right?

Yours,
Eric

-- 
GNU Emacs 24.1.50.1 (i686-pc-linux-gnu, GTK+ Version 2.24.10)
 of 2012-07-08 on pellet
Ma Gnus v0.6