BibSort: Non-consistent sort by author for records without author

[Kennethhole]

Two related bugs:

1. Records without an author are not displayed when sorting by author (unless the complete search result is shown on first page).
2. Records without an author are displayed on top instead of on the button (when you manage to avoid the bug in point one).

Example from the Invenio demo site:

The book collection contains 14 records, whereas 12 have an author. When you choose to display ten results and sort by author, you will see that record 9 and 10 on the first page are the same as 11 and 12 on the second page. This way, it seems like Invenio displays the correct amount of results.

If you change the number of records in the result so that you get all the results on page, the records without an author will appear on the top of the result. In this example, when choosing 25 results on a page, the two records without an author are displayed on the top.

[tiborsimko]

When you choose to display ten results and sort by author, you will see that record 9 and 10 on the first page are the same as 11 and 12 on the second page.

I don't see this on maint-1.1, but I see this on Invenio 1.2.1. To be investigated before releasing 1.2.2.

[ludmilamarian]

I'll take a look as soon as time permits. It might be related with the search results order being changed in the latest version.