Inventory/GUI textures no longer handle translucent pixels correctly

Possibly clones MC-47342.

The bug

If a texture file for an inventory screen is given translucent pixels, those pixels will render completely opaque in-game.

This was not the case prior to release 1.15 for many screens.

Affected screens

Everything located in textures/gui/container (excluding gamemode_switcher.png) is affected by this issue:

• Anvils
• Beacons
• Furnaces, blast furnaces and smokers
• Brewing stands
• Cartography tables
• Crafters
• Crafting tables
• Dispensers and droppers
• Enchanting tables
• Chests (both sizes), trapped chests (both sizes), ender chests, minecarts with chests, barrels
• Grindstones
• Hoppers and minecarts with hoppers
• Horses, donkeys, mules, llamas, trader llamas and camels
• The Survival inventory screen
• Looms
• Shulker boxes
• Smithing tables
• Stonecutters
• Villagers
• Creative inventory screens

In addition, the following are also affected:

• Book-and-quills and written books
• Recipe Book

The advancements window renders translucent pixels correctly.

I am unable to test if the demo screen background is also affected, however the attached resource pack also retextures this.

How to reproduce

1. Download and apply the attached resource pack: translucent-inventories-24w14a-v1.0.zip
2. Enter any of the aforementioned inventory screens

Expected results

The inventory screen would be translucent.

Actual results

It is not.

Further notes

Comparison using another attached resource pack in 1.14.4 and 1.15 respectively: