This fixes a SIGABRT crash in WYPopoverBackgroundInnerView's -drawRect: when the content view controller is a UINavigationController, yet the navigation bar is hidden and the content size height is less than or equal to the navigation bar height (44).
This fixes a SIGABRT crash in WYPopoverBackgroundInnerView's -drawRect: when the content view controller is a UINavigationController, yet the navigation bar is hidden and the content size height is less than or equal to the navigation bar height (44).