Description of the Bug
The furnace recipes to make creosote bottles from coal and charcoal prevent shift-clicking those fuels into the furnace fuel slot. I guess it makes sense that you can shiftclick them into the top slot since they can be smelted but most of the time (char)coal is used as fuel.
Even if the top slot is filled with other items (cobble for example) (char)coal cannot be shift-clicked to go into the fuel slot.

To Reproduce
Test filling a furnace fuel slot with (char)coal, I used crafttweaker to disable the recipe for creosote bottles in the furnace which did in fact restore the old behavior.

Expected behavior
Being able to shiftclick (char)coal into the fuel slot of furnaces, it should work even with those recipes enabled.

Additional context
It's not gamebreaking by any means and in general minor compared to other bugs, maybe there is a clever way to make a nice workaround to get rid of the annoying behavior introduced by this recipe.

fyi, this recipe by any means is to bypass coke ovens and is disabled when coke ovens are available.

Shift-Click behavior is controlled by the block, we can adjust it for our blocks, but not for vanilla blocks.

@liach good to know, I am working with the coke oven from gregic additions since they can share walls.

Gonna just disable the recipe then, thanks for looking into it.