Example provided by mitz: <span style="outline: 1px dotted blue;"> <span style="margin: 0 10px;"></span> text</span> The line is only 1px in height and the text is not displayed. This happens because the root inline box does not learn of the existence of the 'text' run when calculating the line's height.
Created attachment 120655 [details] Patch
Committed r103772: <http://trac.webkit.org/changeset/103772>