[bdowling]

I just checked. TMUX does not insert newlines if there were no newlines in the buffer. That's usually what you want.

[throwaway894345]

Maybe it varies by version, but I get this behavior all the time.

[bdowling]

If you are copying from a text-mode app that does its own word-wrapping by inserting newlines or moving the insertion point, then it may not be possible for TMUX to undo that. Copying from shell output like `cat somefile` or `wget something`, however, works like it's supposed to.