Safari Strip Return Character When Pasting
Thankfully, at some point Apple realize [sic] the problem and fixed it. I don’t remember exactly when. It might have been in Safari 1.2—or Safari 1.3. But they did fix it, in a smart way, by simply stripping the return character altogether when the user pastes a line of text followed by a return character into a single-line text entry field in a Web form.
