Those lines aren’t code, they shouldn’t actually be in code tags, but in samp (I vaguely remember a monk starting a thread here about that, not sure if it’s allowed now), or as a fallback, in pre. Those trailing spaces are insignificant ones, put into the clipboard by a buggy terminal, so yes, it should be the OP who should fix his paste, because it’s broken.

I have turned off the wrapping indeed, because those +-prefixed lines looked horrible and made things harder to read. 99.99% of code tags fit in my screen, so I don’t need CSS to mangle people’s code for me — in fact, that would make things just as bad as the PerlMonks default code mangling.