Git on OSX committing a case change in the fileame.

gistfile1.txt

[/tmp/case]
mark@Dymek:$ git init
Initialized empty Git repository in /private/tmp/case/.git/

[/tmp/case] (master)
mark@Dymek:$ touch foo

[/tmp/case] (master)
mark@Dymek:$ git add foo

[/tmp/case] (master)
mark@Dymek:$ git commit -m 'initial'
[master (root-commit) 44edd4b] initial
 1 file changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 foo

[/tmp/case] (master)
mark@Dymek:$ l
total 0
drwxr-xr-x   4 mark  wheel   136B Nov  8 15:50 ./
drwxrwxrwt  12 root  wheel   408B Nov  8 15:50 ../
drwxr-xr-x  14 mark  wheel   476B Nov  8 15:51 .git/
-rw-r--r--   1 mark  wheel     0B Nov  8 15:50 foo

[/tmp/case] (master)
mark@Dymek:$ mv foo Foo

[/tmp/case] (master)
mark@Dymek:$ l
total 0
drwxr-xr-x   4 mark  wheel   136B Nov  8 15:51 ./
drwxrwxrwt  12 root  wheel   408B Nov  8 15:50 ../
drwxr-xr-x  14 mark  wheel   476B Nov  8 15:51 .git/
-rw-r--r--   1 mark  wheel     0B Nov  8 15:50 Foo

[/tmp/case] (master)
mark@Dymek:$ git st
## master

[/tmp/case] (master)
mark@Dymek:$ git mv foo Foo

[/tmp/case] (master)
mark@Dymek:$ git st
## master
R  foo -> Foo