When you paste multi-line text into a single-line text input in Internet Explorer you only get the first line. This is because IE chucks away everything after the first newline-character. Other browsers will simply replace the newline with spaces. This snippet does the same thing for IE. If window.clipboardData exists we're on IE and we should intercept the paste event to replace newlines with spaces.
A Pen by Nico Haemhouts on CodePen.