klipper causes 1 wakeup per second when idle

Just checked the code for the poller and found this comment
"Update: Now there's also support for XFixes, so in case XFixes support is detected, only XFixes is used for detecting changes, everything else is ignored, even Qt's clipboard signals."

So compiling klipper with XFixes should actually solve the problem. Is there any reason not to do it?

It is compiled with xfixes support.
An excerpt from the build-depends:

Source: kdebase-workspace
Section: kde
Priority: optional
Maintainer: Kubuntu Developers <email address hidden>
XSBC-Original-Maintainer: Debian Qt/KDE Maintainers <email address hidden>
Uploaders: Ana Beatriz Guerrero Lopez <email address hidden>, Sune Vuorela <email address hidden>, Fat$
Build-Depends: cdbs (>= 0.4.51), debhelper (>= 6), quilt, cmake (>= 2.6.0),
 kdelibs5-dev (>= 4:4.1.3), libphonon-dev (>= 4:4.2.0),
 libbluetooth-dev, libcaptury-dev, libdbus-1-dev, libnm-util-dev, network-manager-dev,
 libpam0g-dev, libqimageblitz-dev (>= 1:0.0.4-2), libraw1394-dev, libsensors-dev,
 libstrigiqtdbusclient-dev (>= 0.5.8-2), libusb-dev, libxkbfile-dev,
 libxcomposite-dev, libxdamage-dev, libxfixes-dev, libxklavier12-dev,
 libxrandr-dev, libxrender-dev, libxxf86misc-dev,
 libsmbclient-dev, libxcb1-dev, libxine-dev, libstreamanalyzer-dev,
 libfontconfig-dev, libglu1-mesa-dev, sip4,
 libsm-dev, libxcursor-dev, libxft-dev, libxtst-dev, libqt4-opengl-dev,
 libxinerama-dev, libxss-dev, libck-connector-dev, libplasma-dev (>= 4:4.1.3),

As you can see it's compiled with libxfixes-dev, so I guess xfixes is polling the keyboard every second?

Ok. I should have checked that better. Also, doing

#ldd /usr/bin/klipper

shows that it is linked to libXFixes.
But this library is exactly supposed to prevent the need for polling.

This report needs to be forwarded to http://bugs.kde.org

Thank you for your bug report. This bug has been reported to the developers of the software. You can track it and make comments at: https://bugs.kde.org/show_bug.cgi?id=201587

Fixed upstream for KDE 4.4. Looks safe enough to backport to our packages, though.

Fix committed to bzr for the next packaging release.

This bug was fixed in the package kdebase-workspace - 4:4.3.1-0ubuntu3

---------------
kdebase-workspace (4:4.3.1-0ubuntu3) karmic; urgency=low

  [ Jonathan Thomas ]
  * Add kubuntu_95_klipper_wakeup_fix.diff to prevent klipper from waking the
    CPU around once every second (LP: #301338)

  [ Jonathan Riddell ]
  * Add kubuntu_96_pre_kdm_xsplash.diff for
    https://wiki.kubuntu.org/KubuntuKarmicXsplash
  * Remove kubuntu_10_turn_on_kwin_compositing.diff, KWin has good
    detection now

 -- Jonathan Riddell <email address hidden> Fri, 11 Sep 2009 15:48:38 +0100

I'm using kubuntu 9.10 and the problem still seems to be there.
See here the description of what happens
https://answers.launchpad.net/ubuntu/+source/kdebase-workspace/+question/89486