The bug
It seems that whenever the game shows the text of an hoverEvent (caused by /tellraw
, hovering over an item in the inventory...) it changes the lighting of entities.
Affected entities
Displayed block of minecarts (darkens)
Ender crystal (brightens)
How to reproduce
Place a minecart displaying a block:
Example command
/summon minecart ~ ~1 ~ {DisplayTile:"minecraft:quartz_block",CustomDisplayTile:1b,DisplayOffset:16}
Stand in front of it (South direction; +Z) and look at it (looking North; -Z)
Use the following command and hover over the text:
Example command
/tellraw @a {"text":"","extra":[{"text":"Hover over this text","color":"white","hoverEvent":{"action":"show_text","value":"You are hovering over this text"}}]}
→ You should see that the block being displayed darkens when you are hovering over the message.
Code analysis
The following is based on a decompiled version of Minecraft 1.9 using MCP 9.24 beta.
It looks like the method net.minecraft.client.gui.GuiScreen.drawHoveringText(List<String>, int, int)
which calls the method net.minecraft.client.renderer.GlStateManager.enableRescaleNormal()
is causing this.
Fixed between 15w42 and 15w45a