If width - border radius - border width goes negative, the shadow misses rounded corner. Only happens on ToT so http://trac.webkit.org/changeset/76083 has this regression. I'll post the fix in a few days.
Created attachment 79696 [details] a repro.
Created attachment 79888 [details] Patch
Simon, Mitz, could you take a look at this? It should be a kind of obvious....
Ping. Simon? I'd like to fix this regression soon because this actually breaks things... (In reply to comment #3) > Simon, Mitz, could you take a look at this? It should be a kind of obvious....
Comment on attachment 79888 [details] Patch Looks sane to me.
Committed r77105: <http://trac.webkit.org/changeset/77105>
Landedl. Thanks Eric!