Bug 106995

In the case of two sibling boxes, the first specifying break-after: always and the second break-before: always, there should be only one break generated and no empty fragmentainer. "A forced break then occurs at (1) if, among the ‘break-after’ properties specified on or propagated to the earlier sibling box and the ‘break-before’ properties specified on or propagated to the later sibling box there is at least one with a forced break value. When multiple forced break values apply to a single break point, they combine such all types of break are honored and no content-empty page boxes are generated, except for at most one content-empty page as may be required by the forced break values to position ensuing content on a specific type of page. When ‘left’, ‘right’, ‘recto’, and/or ‘verso’ are combined, the value specified on the latest element in the flow wins."