unstructured

d570f462 - Fix sort_page_element. ensures that sorting is stable and not random. (#3978)

Fix sort_page_element. ensures that sorting is stable and not random. (#3978) The sort_page_element() use the element id to sort the elements. Two executions of the same code, on the same file, produce different results. The order of the elements is random. This makes it impossible to write stable unit tests, for example, or to obtain reproducible results.