It is still hard to select text in URL bar with an inverted selection handle. We can improve the issue by replacing the Y coordinate of selection point with Y coordinate of start caret for single line input filed. Thus, the Y coordinate is always valid regardless of the actual location of the selection handle.
Created attachment 197857 [details] Patch
Comment on attachment 197857 [details] Patch LGTM.
Comment on attachment 197857 [details] Patch Clearing flags on attachment: 197857 Committed r148302: <http://trac.webkit.org/changeset/148302>
All reviewed patches have been landed. Closing bug.