4c29604e1e
We skip window animations while the overview is shown (and the window group is hidden) to avoid unnecessary work. However when an attached modal dialog is opened or closed, this involves checking whether the parent window should be dimmed - skipping that test means that we can simply fail to dim or undim a window altogether, so do that check unconditionally. https://bugzilla.gnome.org/show_bug.cgi?id=762475