[css3-flexbox] flex-line-pack and stretch

The description of how line cross size is determined in multiline flexbox assumes that line height depends only on items in the line. It doesn't have an option for line to stretch to available cross-size of flexbox.



That creates a problem: a multiline flexbox with only one line behaves differently from a single-line flexbox -- it is not possible to align all items to flexbox, it is only possible to align with siblings.



There should be an option to make lines stretch to flexbox. One way to do that is to add



     "flex-line-pack:stretch"



value, which would stretch all lines equally in cross direction to fill flexbox -- as if their cross size was flex(1 auto).



What do you think?