Steps to reproduce: 1. Open https://bugs.webkit.org/show_bug.cgi?id=19951 (as an example of a bug with a long summary). 2. Click in the beginning of the summary, and drag to the right. Results: the visible part of the summary is selected, but the text field is not scrolled. Tested with r35406 local build; works fine with shipping Safari/WebKit.
<rdar://problem/6110367>
Created attachment 22544 [details] Patch with layout test
fixed in r35433