The brewing stand GUI does not have container sprites for the fuel and potion output slots

Can confirm.

I think it is WAI, if you change potion bottle texture you can see it's not actually hidden but just seamlessly covered.
See for yourself with this resource pack : https://66ed39aec3765da25cfb6002b5fe7930221b5f18.googledrive.com/host/0Bwh-rUpGiETGWEtvc3E5Rm5zdE0/for%20MC-74408.zip (Virustotal result : https://www.virustotal.com/file/8c40901c939fb8f85c0ae5dff7136d06c801ec0b52abe8fd90c327fba673b324/analysis/1418862189/)

@unknown, that's exactly what I'm saying: it should get hidden - and not seamlessly covered - when you put a bottle on top of it, but it doesn't. I just don't think it works as intended because it doesn't follow the patterns for the other GUIs, like the armor one.

confirmed for 15w31b

Fixed little grammar issue in the title; added 1.8.8.

Still here up through 16w38a. It also applies to the blaze powder slot – try /replaceitem block ~ ~ ~ slot.container.4 ghast_tear to see it easily.

Thanks! I added a screenshot of it.

Note that while ghast tears in that slot are not supported, resource packs giving different textures to blaze powder should still hide the icon.

Confirmed for 1.13.1.

Affects 1.16-rc1

Affects 1.16.1 and 20w27a

Can confirm in 21w05b.

Can confirm in 1.19.2.

Requesting ownership for this issue. The original reporter as not updated the issue, and so it has since become outdated and innacurate. I would like to update the post.
Below are some of the things to note now:

1. The player is no longer able to insert anything other than blaze powder into the fuel slot

While the blaze powder texture is still baked into the texture of the GUI, there can no longer be any visual conflicts shown like in "4.png" with the ghast tear.

Source (from BrewingStandMenu class):

public boolean mayPlace(ItemStack itemStack) {
         return mayPlaceItem(itemStack);
      }

      public static boolean mayPlaceItem(ItemStack itemStack) {
         return itemStack.is(Items.BLAZE_POWDER);
      }

2. The armor and off hand slot background/borders in the player inventory GUI texture are no longer baked in, but rather dynamically uses item textures now

Textures used:
empty_armor_slot_helmet.png
empty_armor_slot_chestplate.png
empty_armor_slot_leggings.png
empty_armor_slot_boots.png
empty_armor_slot_shield.png

3. The llama & horse GUI texture are the same

Both entities share the same GUI texture, which currently does not allow for the item slots to render dyanmically.

(Currently though, this is less of an issue as there are no visual issues with this GUI. All the applicable item textures allign with their slot backgrounds)

4. The Enchantment table GUI texture recently updated and still has the lapis lazuli texture baked in

This is not necessarily an issue, but is relevant to the report still.

5. The Smithing table GUI texture no longer has this issue

The smithing table got an overhual, and no longer has the issue as all the item slots render dynamically.

Smithing table is no longer affected.

(Leaving a comment to note me updating the post)
This issue is no longer present for the enchanting table, or the horse/llama gui textures as of 23w31a. The only GUI affected by this issue now is the brewing stand. (Which notably is the only GUI not changed in 23w31a)

(Old title: Dynamic rendering of item slot textures is not consistently used for all GUIs)

Requesting that 1, 2, 3, and 4.png be removed from the issue as they are no longer related, and provide no valuable information.

That's because you kinda changed the scope of the report from not hiding to not separate. Seeing recent changes, that's fine (since it's no longer 1:1, and a separate report for the not hiding got made), but those images were relevant to the report.

Take this as a reminder that changing scope is generally not to be done to a report.

I'll remember that, thanks for letting me know. 👍

For the record, that ticket is MC-265033, which should absolutely be marked as related.

This has somehow made it into the full release of 1.20.2.