Why is it bad to commit lines with trailing whitespace into source control?

Question

Why is it bad to check in lines with trailing whitespace to your source control? What kinds of problems could that cause?

Answer 1

False differences, basically. It's helpful if diffs only show "real" changes. Some diff programs will ignore whitespace, but it would be better just to avoid the dummy change in the first place.

Of course, it also doesn't help if it makes the line wrap on a colleague's machine.