side by side diff: missing code when scrolling
In a side by side diff of a file that is longer than screen height, when scrolling on one side, the code lines on the other side stop at some point, showing a blank area. When you move your mouse to the other side and scroll there, the missing line suddenly reappear. This behavior also happens when scrolling from 'the other side'.
Seen on Linux, Firefox 33.0 (not tested on other platforms/browsers).