bug#6637: 24.0.50; kill ring being seriously polluted

[Chong Yidong]

Angelo Graziosi <angelo.graziosi@alice.it> writes:

>> Go to any X application (firefox, etc) with a text field.
>> Holding shift, press the arrow keys and select some text.
>> Release shift, and press another down arrow to deselect it.
>>
>> In Emacs 23 (in the absence of latest changes):
>> Run `emacs -Q'.
>> C-y
>>
>> The text you selected is yanked into the buffer.  This is because the
>
> I have done *exactly* what you suggest on Kubuntu 10.04, with GTK
> build of Emacs24 trunk rev.100832: it DOS NOT paste the selected text
> but garbage (something in the clipboard form previous selections...)

I tested the recipe a vanilla build of Emacs 23.2 from the tarball, with
`emacs -Q'; the selected text is indeed pasted.

However, it seems that the behavior of Firefox differs from that of
Gedit and Openoffice; those disown the selection after deselection.
Perhaps the behavior of Firefox is aberrant.  Assuming the latter is
more standard, I will look into changing Emacs' behavior to follow it.