Darker areas on enchanted_item_glint texture are rendered transparent in UI

Worn enchanted armor is transparent in the UI. The darker areas of the enchanted_item_glint texture render the armor transparent. It's noticeable in Vanilla, and even more so with texture packs that have custom glint textures.

 

In the video below, you can see the trees through the armor. 

In the images, its a texture pack with a darker glint texture, causing the UI to be completely transparent.