Question

I moved a file using git mv. Now I would like to do a diff on the new file to compare it with the old file (with the old, now non-existent name).

How do I do this?

Answer 1

You need to use -M to let git autodetect the moved file when diffing. Using just git diff as knittl mentioned does not work for me.

So simply: git diff -M should do it.

The documentation for this switch is:

-M[<n>], --find-renames[=<n>]
       Detect renames. If n is specified, it is a threshold on the similarity index 
       (i.e. amount of addition/deletions compared to the file’s size). For example, 
       -M90% means git should consider a delete/add pair to be a rename if more than
       90% of the file hasn’t changed.