Tracking "requested variants" and ways to "get rid of" outdated ones

[Clemens Lang]

Hi,

----- On 19 Feb, 2015, at 12:18, Mojca Miklavec mojca at macports.org wrote:
> I like variants. But I believe that many of us are often bitten by the
> inability to "get rid of" outdated variants without manual
> intervention.

Fully agree. We should have an additional field in the registry database
that contains "requested variants" in addition to the currently implemented
variants field. Only requested variants should be taken into account during
upgrades.

> I don't know how to properly handle that, but are there any chances to
> at least track whether the user intentionally switched a variant
> on/off/picked another variant? If we had that information the upgraded
> port would have at least some chances to switch to the new default
> variant (providing the user didn't explicitly mess with the variants
> in that particular port). This would also be a lot more useful for
> statistics (mpstat).

We do not currently track this info. Base needs to be modified to provide
it. A new database column needs to be added in base/src/cregistry/sql.c
together with an upgrade path from the previous version. Some database
glue code may need to be added, but that should be easy because the field
would behave exactly like the existing variants field. Then, we'd need to
modify the base code to actually fill in the field and use it during
upgrades.

-- 
Clemens Lang