Issue with 'git diff' and non ascii characters

Hello,

I have spotted a problem using 'git diff' when non ascii characters are involved. Not sure if the problem is due to the name of the file, or its content.

Cheers,

Giulio Cesare

Steps to reproduce the problem:

$ sw_vers
ProductName:	Mac OS X
ProductVersion:	10.9.4
BuildVersion:	13E28
$ git --version
git version 1.8.5.2 (Apple Git-48)
$ mkdir test
$ cd test
$ echo prova > tèst.md
$ git init
Initialized empty Git repository in /private/tmp/test/.git/
$ git add *
$ git commit -m "first commit"
[master (root-commit) ebbe2a3] first commit
 1 file changed, 1 insertion(+)
 create mode 100644 "t\303\250st.md"
$ echo provà > tèst.md 
$ git status
On branch master
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

	modified:   "t\303\250st.md"

no changes added to commit (use "git add" and/or "git commit -a") $ git diff tèst.md $