bug in t3700-add.sh?

Hi,

Running test 17, I got this output:

* expecting success:
        git rm --cached -f file symlink &&
        (
                echo "100644 $(git hash-object -w stage1) 1     file"
                echo "100755 $(git hash-object -w stage2) 2     file"
                echo "100644 $(printf $s | git hash-object -w -t blob
--stdin) 1        symlink"
                echo "120000 $(printf $s | git hash-object -w -t blob
--stdin) 2        symlink"
        ) | git update-index --index-info &&
        git config core.filemode 0 &&
        git config core.symlinks 0 &&
        echo new > file &&
        echo new > symlink &&
        git add file symlink &&
        git ls-files --stage | grep "^100755 .* 0       file$" &&
        git ls-files --stage | grep "^120000 .* 0       symlink$"

rm 'file'
rm 'symlink'
printf: usage: printf [-v var] format [arguments]
printf: usage: printf [-v var] format [arguments]
100755 3e757656cf36eca53338e520d134963a44f793f8 0       file
120000 3e757656cf36eca53338e520d134963a44f793f8 0       symlink
*   ok 17: git add with filemode=0, symlinks=0 prefers stage 2 over stage 1

I don't know if "printf $s" was intentional because $s was empty and caused printf to print out help usage. I have feeling that there is something wrong here. Anyone can clarify?

Johannes Sixt CC'd as he added this code.