The attached patch against JWM 578 ("jwm-578-randr_without_randr.patch") improves the reliability of screen resizing and rotating with the X server extension RandR and the command line tool xrandr. It does that by making JWM aware of changes to the root window dimensions in the most simple and straightforward way possible. XRandR-awareness of the window manager is *not* needed for resizing or rotating: with this patch, both will work even if JWM is compiled with "./configure --disable-xrandr".
The patch does not re-size or re-position client windows. What it does instead is to make the change of screen width, height, and rotation *reliable*.
The patch has successfully passed serious testing (see the attached document "jwm-578-randr_without_randr.tests.README" for the details), although on a limited range of hardware and in single-monitor setups. (I don't say that it doesn't work in multi-monitor setups. I only say that I haven't tested it.)
Questions? => Please ask.