I've recently run into an issue with white-space: nowrap which is reproducible with the latest WebKit nightly. Broken: <div style="width: 200px; overflow: hidden"> <div style="float: left; width: 50px; height: 50px; background-color: red"></div> <span style="white-space: nowrap">Some long string that wraps</span></div><!-- </div> not on next line on purpose - triggers bug --> Works: <div style="width: 200px; overflow: hidden"> <div style="float: left; width: 50px; height: 50px; background-color: red"></div> <span style="white-space: nowrap">Some long string that wraps</span><!-- text node (space or newline) here fixes the bug --> </div> Essentially, the white-space: nowrap span (or any inline element) should wrap below the float: left block if it doesn't fit, and should only spill out of its parent if it doesn't fit within the width of its parent after wrapping. Adding a space or newline after the white-space: nowrap span causes it to behave correctly. Note: Overflow hidden on the parent is not necessary, but it makes this scenario clearer.
This appears to behave the same in Safari 4.0.3 as well.
Created attachment 171084 [details] Patch
Comment on attachment 171084 [details] Patch LGTM. A link to the bug in the ref test would be nice :)
Comment on attachment 171084 [details] Patch Clearing flags on attachment: 171084 Committed r132935: <http://trac.webkit.org/changeset/132935>
All reviewed patches have been landed. Closing bug.