Fix flicker on hover After an update to the newest X with mesa drivers (radeon), simdock started to flicker. Turns out this was caused by changing icons y-variable always by zoomChange, even when reducing the change for width and height in the last steps to not step over, thus replacing the icon a bit (stepping over the paintarea?). It's unclear to me why this lead to flicker now.
img->y += img->h - img->w; // we don't want to set this in different steps than the width, as this leads to hidden images under current X with Mesa 10.4.0-devel