[description]

Instead of removing an entry from the index and adding one with the same name, you can also directly update that entry!

Put the content you want in a file with a matching name, and then run

    git update-index <file>

This will create a new blob, and update the hash of the entry to that blob.

Update an entry in the index!

[setup]

echo "file 1" > file1
echo "file 2" > file2
echo "file 3" > file3
git add .

[setup goal]

echo "file 1" > file1
echo "file 2" > file2
echo "file 3" > file3
git add .

echo "new content" > file1
git update-index file1

[win]

# This is not really a good test for the winning condition...
test "$(git ls-files -s | git hash-object --stdin)" != "10c4b28623e7e44e09f5a596450a50ab7ac31fbe" -a "$(git ls-files | wc -l)" -eq 3
