Bug in OneBox, very annoying. If you copy some text and last symbol is space, when you paste it, after space there will be extra “newline”. You can test it by double-clicking on any word in this text with space after it, copy and paste in in OneBox. I tested this with text editor - pasting there gives normal result, so it’s issue with pasting in OneBox, not copying from OneBox. I also tried to copy word with space from text editor and paste it in OneBox - yea, “newline” apears on pasting.
P.S. I’m not sure if this important or not, but I use latest FireFox.