Before this patch, empty values were not hashed at all. Which had the unfortunate side-effect
that e.g. the lines
TEST -
and
- TEST
have the same hash values. On re-reads that means that the change will
be ignored.
This is probably pretty academic, but this patch changes it and adds a testcase.
Output of the reread test changes due to re-ordering of the output (probably
due to the fact that the internal hash values are changed and thus transferred
in a different order)
