It's simply due to Distribution not inheriting from lp.code.model.hasbranches.HasMergeProposalsMixin, and to the external API interface having no support for adapters. If it had support for adapters, we wouldn't need to remember to expose it.
However, that's a separate (trivial!) bug.
It's simply due to Distribution not inheriting from lp.code. model.hasbranch es.HasMergeProp osalsMixin, and to the external API interface having no support for adapters. If it had support for adapters, we wouldn't need to remember to expose it.
However, that's a separate (trivial!) bug.