When inside a file that is part of `org-agenda-file`, the default scope to
search for locations via `db/org-get-location` (used for example when
interactively inserting links) is extended to include all agenda files, and not
only the current buffer. The idea behind this is to consider all agenda files
as one large data collection, and not only individual files. This inhibits the
usual error, when trying to insert links at items located in refile.org, that
links are only displayed for items in refile.org itself – which are usually not
many – when instead links to items in the default org files where actually
requested.
This should not be an issue for performance, as searching through all agenda
files for valid locations is fast even on Windows.