Created attachment 116570 [details]
Screenshot showing pixels copied from underlying window (before moving the corrupted window)

I'm seeing a wierd rendering problem where pixels from an unrelated window underneath (e.g. a terminal) are copied into part of the background of the "Insert Indexes & Tables" dialog when it first opens.

This happens for me using 5.0.0.0.beta1 but *not* in any earlier version.  It's hard to see how LO by itself could do this even if it wanted to; maybe something it is doing differently now tickles an X.org bug ... ?   FWIW, Ubuntu uses a compositing window manager.

==> Please see the attached screen-shot.

STEPS TO REPRODUCE:

1. Open attached "new.odt" document.
2. Place cursor below the paragraph which says "INSERT TABLE ... BELOW HERE"
3. Insert->Indexes and Tables->Indexes and Tables...

(it seems to depend on the positioning of the windows; it happens most often if the main window is the full height of the monitor, and about in the middle of the screen)