Return the result of the parent class on_key_press_event handler to prevent the overriden handler from stealing all keyboard input.
Return the result of the parent class on_key_press_event handler to
prevent the overriden handler from stealing all keyboard input.

freedesktop-unofficial-mirror/poppler__poppler-glibmm,freedesktop-unofficial-mirror/poppler__poppler-glibmm,freedesktop-unofficial-mirror/poppler__poppler-glibmm