SUMMARY This bug first appeared in Slackware 14.1 or KDE 4.10.5 packages and is prevalent in the latest release (Slackware 14.2) and -current development version. The correct behavior where the screensaver grabs the root window (i.e. not the default wallpaper screen) was last observed in the KDE 4.8.5 packages (Slackware 14.0). The offending code appears to be in the kdebase module or kde-workspace package. When running the kscience screensaver in 'demo' mode the correct behavior is evident where the screensaver grabs the X root window. When running the screensaver in  normal operation using the the inactivity timer the code renders the default wallpaper screen instead of the X root window.


STEPS TO REPRODUCE
1. System Settings->Display and Monitor->Screen Saver->Desktop Distortions-Science
2. Set Start automatically and set time (e.g. 1 minute) 
3. Wait till screensaver activates

OBSERVED RESULT
Screensaver activates but renders default wallpaper screen (Elarun)

EXPECTED RESULT
Screensaver should render the current root window screen.


SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: Linux kernel 3.10.17/kdeplasma-addons-4.10.5 x86_64-1
(available in About System)
KDE Plasma Version: 4.10.5
KDE Frameworks Version: (? could not determine this)
Qt Version: 4.8.5

ADDITIONAL INFORMATION
I can only get correct screensaver behavior by reverting the kde-workspace package to version 4.8.5 but this breaks other things due to compatibility issues.