I have installed gnome-shell-3.10.4-2.fc20.x86_64, downloaded the patch, and
then applied it manually. It causes the problem. That means there is no other
problem in packaging, build environment, etc; it's the code. Also, I have
seen the problem on Intel graphics, therefore it's not tied to any particular hw
and it should be trivial to reproduce (as long as you have hundreds+ of music
files). You can see it very easily if you try to clear the search box in
Rhythmbox. Without the patch it's cleared immediately, with the patch it takes a
second or two.