Here’s a very handy tip posted on Andrei Zmeivski’s blog today:
Pasting Wrapped URLs
Here’s another Mozilla/Firefox tip: if you copy a URL wrapped over multiple lines from somewhere and try to paste it into the address bar, you will end up only with the first line of it. To fix it, go to about:config and change
editor.singleLine.pasteNewlinessetting to 3 or add:
to your user.js file. Now all the line breaks will be removed upon pasting.