Removes an error trap pushed with gdk_error_trap_push(). May block until an error has been definitively received or not received from the X server. gdk_error_trap_pop_ignored() is preferred if you don’t need to know whether an error occurred, because it never has to block. If you don't need the return value of gdk_error_trap_pop(), use gdk_error_trap_pop_ignored().
Prior to GDK 3.0, this function would not automatically sync for you, so you had to gdk_flush() if your last call to Xlib was not a blocking round trip.
X error code or 0 on success