Consider an XML file consisting of one long line of text. A diff would not be very useful in that case.
I guess an XML aware diff could work though? certainly not at all line based...
If it did node-based diffs.
Most diffs do that. The Diff that ships with gvim on Windows has this option on by default and I couldn't find where to turn it off because it was severely screwing up what I was diffing.
That's because XML does not guarantee order of elements.
"That's because XML does not guarantee order of elements."
It better, or else it's broken. In XML, element order matters. Attribute order does not.