Created attachment 43564 [details] test-case illustrating the problem Given and empty Canvas, checking the (default) value for shadowColor yields "black". fillText doesn't take this in account. When setting shadowColor explicitly to "black" and calling fillText, it does render with shadow. The problem is that the default value for shadowColor shouldn't be "black" but "rgba(0,0,0,0.0)". Attached a small test case and screenshot of the corresponding incorrect result.
Created attachment 43565 [details] result of the attached test-case
Unless I'm misunderstanding your test case, this appears to be working properly now in Safari 5. Your test-case renders two identical hello worlds and then shows the writln as rgba(0,0,0,0.0)
Created attachment 60973 [details] Standard Safari 5 still seems to have issue. Safari 5 here still shows two different renderings and black as default value. Maybe you mean Safari 5 with a nightly webkit build ? Added attachment including Safari 5 about dialog.
Right you are - my fault. ToT build from this morning on SnowLeopard sees it fixed. Could you check this as well for yourself?
Created attachment 61026 [details] Nightly Build r62632 fixes issue