Lower a client-supplied ordering onto an inline child list, or refuse the shape

A client that asks an inline child list for an ordering gets it, instead of getting a build that stops. Today this schema

fails the build with a generator-bug throw from the plan tier. It used to generate silently and serve the actors in whatever order the database returned them, which is the defect the throw replaced: an inline child list is projected as a correlated multiset, the multiset command carries the coordinate’s whole resolved ordering, and the projection renderer lowers the fixed arm of that ordering alone. A client-supplied order was therefore accepted and dropped. Lowering the argument arm onto the multiset closes it and the throw’s population empties on its own; refusing the shape at its coordinate with an author-facing rejection is the smaller alternative, and which of the two ships is this item’s question. Whichever lands, the exemption-free invariant in LauncherCommands.requireResolvedOrderingsAreLowered is what stops the silence returning.

The shape is not exercised anywhere in this reactor, which is why the throw ships rather than a rejection or an exemption list: a consumer meets it, our corpus does not. The confirmation that the ordering really was dropped is recorded on the item that filed this one, and LauncherOrderingClosureTest.anInlineChildListCarryingAnOrderByArgumentIsRefusedAtProduction is the case that pins today’s behaviour and is the case to rewrite when the lowering lands.