Item models generated from textures containing adjacent opaque and translucent pixels do not have expected internal geometry

The bug

If an item has a model which is pointed to item/generated, and the texture used contains a fully opaque pixel next to a partially transparent pixel, there is missing internal geometry that makes the item look weird as a result.

It'd be expected that there would be texture planes which would mark the boundary between a translucent pixel and an opaque pixel, however such planes are absent, making the item look strange since the opaque pixels have an invisible interior.

How to reproduce

A resource pack is attached to this ticket. Sticks and blaze rods are both assigned the same image as a texture. Sticks generate their model via item/generated, whereas blaze rods are assigned a manually-created model file to reflect the expected appearence.

Expected results

Sticks would look identical to how blaze rods look with this resource pack.

Actual results

They do not - internal planes are missing.

Further notes

Any visual gaps in the model are a result of MC-73186 - the model itself is fine.