In the most recent nightly build, changing the disabled state of a textarea does not do a repaint, thus, the textarea still appears as before even though the status has changed. As soon as the user (e.g.) resizes it, it's repainted and the status is reflected. This worked in Safari 3.1. This behavior seems to be broken on textareas. I tested this checkboxes and textfields (input type=text) and it seemed to work correctly for those, but not for textarea.
URL: http://dump.kkaefer.com/disabled.html (This is not necessarily restricted to Mac OS X 10.5, but I can only confirm it for 10.5)
You might not see the effect when clicking on the link for the first time. After you reload the page, the bug should appear.
This seems to be a recent regression. ToT fails his test case, but my unreleased Safari build from several months ago does not.
The bug does not reproduce on ToT (not sure when it was solved). I haven't found out a repaint test for this case so I will turn the original test case into one and land it.
Created attachment 118469 [details] Proposed change: land a repaint test covering the existing test case.
I can confirm that the original bug I reported is fixed in current builds.
Comment on attachment 118469 [details] Proposed change: land a repaint test covering the existing test case. Clearing flags on attachment: 118469 Committed r102399: <http://trac.webkit.org/changeset/102399>
All reviewed patches have been landed. Closing bug.