[BUG] Incomplete calendar view for anchor METS URL after partial indexing

[stweil]

Description

The newspaper calendar view which should show all years only shows a selection of years.

Reproduction

Steps to reproduce the behaviour:

1. Run viewer with URL of an anchor METS file of a newspaper. It shows all years.
2. Index a subset of the years.
3. Run viewer like in (1). It now shows only the years from the indexed subset, but the table of contents on the left side still shows all years.

Expected Behavior

The calendar view should always show all years if it is called with a URL.

[stweil]

The table of contents seems to use the URLs for the year METS files while the calendar does this only if no year was indexed. Otherwise the calendar uses the document id.

Maybe both table of contents and calendar should use the same kind of addressing for the single years. Would there be disadvantages if tx_dlf[id] would always point to the METS URL instead of the current mix where sometimes the document id is used?