When comparing the text rendering on http://www.redhat.com/magazine/009jul05/features/execshield/ between Safari 3 and TOT, it is clear that TOTs rendering is much bolder. It seems like the text may be being painted twice. Bisecting the revision history with git revealed that the problem originates with <http://trac.webkit.org/projects/webkit/changeset/29834>.
Created attachment 18806 [details] Reduction
<rdar://problem/5716722>
Created attachment 18807 [details] Avoid making blocks paint floats that intrude into them
; in that case...??? You sir, have a case of sentence truncation!
Comment on attachment 18807 [details] Avoid making blocks paint floats that intrude into them Sam also pointed out that the isDescendantOf() can be expensive. I think I can avoid it in most cases.
Created attachment 18809 [details] Avoid making blocks paint floats that intrude into them
*** Bug 17117 has been marked as a duplicate of this bug. ***
Comment on attachment 18809 [details] Avoid making blocks paint floats that intrude into them r=me
Fixed in <http://trac.webkit.org/projects/webkit/changeset/29885>.
*** Bug 17120 has been marked as a duplicate of this bug. ***