This reverts commit 462163e.

Empty subjects should be permissible.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from #5627)

This reverts commit f2982ad.

Empty Subjects should be permissible.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from #5627)

Commit 87e8fec (16 years ago!) introduced a bug where if we are
attempting to insert a cert with a duplicate subject name, and
duplicate subject names are not allowed (which is the default),
then we get an unhelpful error message back (error number 2). Prior
to that commit we got a helpful error message which displayed details
of the conflicting entry in the database.

That commit was itself attempting to fix a bug with the noemailDN option
where we were setting the subject field in the database too early
(before extensions had made any amendments to it).

This PR moves the check for a conflicting Subject name until after all
changes to the Subject have been made by extensions etc.

This also, co-incidentally fixes the ca crashing bug described in issue
5109.

Fixes #5109

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from #5627)

It is quite likely for there to be multiple certificates with empty
subjects, which are still distinct because of subjectAltName. Therefore
we allow multiple certificates with an empty Subject even if
unique_subject is set to yes.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from #5627)

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from #5627)