Transparency bug

I think it's a bug...
#1

Here im using the GBColor.pal the transparency is set to be the 1st color in the palete which is #000000
Only 2 layes filled with 1 color each, the first layer is filled with a random color and the second only an area is filled with another color if i save this as an image it should show me a square with 2 colors but instead it only shows me the color in layer 2 and all the layer 1 is transparent.(ex1)

(ex1)Now if i put the color set as transparent in a random place and save as image the image will be exactly the same as ex1 but it will show the transparent color as a black.

Instead if i fill with the transparent color the the top left corner and save as a image the image will show me the layer the transparent color as a black dot and the second layer will be transparent but i cant see the color behind it.(ex3)

If i fill the botton left corner and the top left corner it will show the 2 layers and the transparent colors will be transparent(ex4)

examples

[Album] promotionbug

pmp files

I speak spanish so excuse my grammar

#2

Indeed. This is a bug. I used example1 and what happens is that the layers are merged when saving but instead of storing the transparent color 0 to the png/gif file it stores the color as transparent that displayed on the second layer where the first layer uses color 0 (and is transparent). It does not happen if you manually flatten the layers and store the file.
Will fix with next maintenance patch.