Reported by Anton Prowse

This is Issue 288: http://wiki.csswg.org/spec/css2.1#issue-288

When there are multiple narrow floats inside multiple narrow containing blocks themselves inside some wide parent containing block, a horizontal line drawn through the parent quite possibly passes through more than one positive-width 
spaces before, after and between the floats.  Since the line boxes of that parent need to somehow be placed around the floats, it needs to be clarified that at most /one/ of those spaces is occupied by a shortened line box (ie the line box isn't fragmented), and clarified /which/ of those spaces is occupied.  

We can easily address both issues by stating that no line box can be to the left of a left float, nor to the right of a right float.  That information is currently missing from the spec, which says where content _can_ go but omits to say where content _can't_ go.

There is currently no interop on this issue.

David Baron proposes (updated to match current spec wording):

In 9.5, change:
  # However, the current and subsequent line boxes created next to
  # the float are shortened as necessary to make room for the margin
  # box of the float.
into:
  # However, the current and subsequent line boxes created next to
  # the float are shortened as necessary to make room for the margin
  # box of the float: the left edge of a line box must not be to the
  # left of the right margin edge of any left float next to it and
  # in the same block formatting context, and likewise for the right
  # edge and right floats.


Conversation begins:
http://lists.w3.org/Archives/Public/www-style/2009Aug/0519.html

Bug description: http://lists.w3.org/Archives/Public/www-style/2011Mar/0340.html (last part: FL3)

Proposal: http://lists.w3.org/Archives/Public/www-style/2011Mar/0346.html


Issue 288: http://wiki.csswg.org/spec/css2.1#issue-288

Summary
    Clarify flowing line boxes next to floats
URL
    http://lists.w3.org/Archives/Public/www-style/2010Mar/0366.html
Proposal
    http://lists.w3.org/Archives/Public/www-style/2011Mar/0346.html (end)
Status
    Not changed. =errata=