[bug][0.4.13] Weird glass bug

[Fixerol]

This is very weird glass bug on Extreme Survival Minetest (that could possibly be on default one too)... I have no idea wth is this. Confirmed by other person. What is interesting is it changes colours periodically... from orange to blue or whatever (but I have not observed exact moment).
Specs: MT 0.4.13 64bit msvc on Win7 64bit, ATI Radeon HD 6870, Catalyst 15.7.1

+ Spoiler

anisotropic_filter = true
bilinear_filter = false
connected_glass = true
enable_bumpmapping = true
enable_parallax_occlusion = true
enable_waving_leaves = true
enable_waving_plants = true
enable_waving_water = true
fsaa = 0
generate_normalmaps = true
leaves_style = fancy
maintab_LAST = multiplayer
menu_last_game = minetest
mip_map = true
name = Fixer
server_dedicated = false
trilinear_filter = false
language = en
cinematic = false
creative_mode = true
fixed_map_seed =
free_move = true
mainmenu_last_selected_world = 3
mg_name = v7
public_serverlist = true
fps_max = 120
viewing_range_nodes_min = 70
wanted_fps = 75
address = 23.28.75.103
remote_port = 30000
enable_minimap = true
minimap_shape_round = false
sound_volume = 0.5
fast_move = false
noclip = true
selected_world_path = D:\Games\Minetest\minetest-stable\bin\..\worlds\CarboWorld
world_config_selected_mod = 1
active_block_range = 1
enable_damage = true
server_announce = false
wieldview_node_tiles = false
wieldview_update_time = 2
port = 30000

Screenshot:

[Dragonop]

I have seen it too on some of the servers OldCoder hosts. With a difference, the glass is not "filled" with colour, it has some sort of "carpet" inside it. Aside from that, it's the same.

[Don]

Is that under water?

[Fixerol]

Is that under water?

yes

[Fixerol]

Today it is green... wth is going on?

[Dragonop]

Fixerol, you lucky! Mine are always orange or light blue!

[est31]

That's thanks to the param2 being non-zero. If its non-zero, the param2 displays some "interior volume level" of some sort. It has been added by commit ea6c3835debfffa22163f048eae57928311143c4 . I don't know why RBA added it, ask him.

But its no bug.

[Fixerol]

But its no bug.

m? o.O

[Dragonop]

est31: it is not working as it should be, so it is a bug.

[est31]

Only if something isn't expected doesn't mean its a bug. If you don't like these "volume levels", then remove the glass block and place it again. The param2 should be reset to 0.

[RealBadAngel]

This is not a bug, but improper use of glasslike framed drawtype. Param2 is meant for interior volume level, special tiles shall hold textures for it. Its meant for water/lava or whatever tanks etc.
Sample mod that uses it is plasma lamp for example:
https://github.com/RealBadAngel/plasma_lamp

[Amaz]

I think that https://github.com/minetest/minetest_game/pull/712 will help with this.

[Sokomine]

Nice water tanks! I wonder if it could be used for a barrel (a mesh by now) as well.