squee, returns all data as strings, and expects strings as inputs to
queries. So, keeping the ids as strings was easy initially, but it means that
you can't tell from the type whether it should be quoted, or not...
Therefore, handle ids as strings, converting them to numbers when they're
fetched from the database, and back to strings as part of the queries.
The licenses table, along with the package_metadata table had duplicate
values. This could happen as the unique constraints on those tables didn't
properly account for the nullable fields.
The duplicates in those tables also affected the license_sets, packages,
package_derivations tables in a similar way. Finally, the
guix_revision_package_derivations table was also affected.
This commit adds a migration to fix the data, as well as the constraints. THe
code to populate the licenses and package_metadata tables is also updated.
On one code path, they were handled as numbers, whereas elsewhere they were
handled as strings. This led to the package-metadata code trying to insert
duplicate entries.
Instead, just handle them as strings everywhere.
Store the location a package can be found at, and display this on the package
page.
If available, link off to the git repository containing the package.
I'm thinking about adding more fields to this table, and the sha1_hash values
will make this tricker.
Therefore, remove the value, and adjust the existing code to cope. This commit
also adds a new test which coveres some of the changed functionality.
