Affects Version/s: Minecraft 1.5.2, Snapshot 13w18b, Snapshot 13w18c, Snapshot 13w19a, Minecraft 14w19a, Minecraft 14w20a, Minecraft 14w20b, Minecraft 14w25b, Minecraft 1.8, Minecraft 1.8.1-pre3, Minecraft 1.8.1, Minecraft 1.8.2-pre4, Minecraft 1.8.8, Minecraft 15w49b, Minecraft 16w06a, Minecraft 1.10.2, Minecraft 16w33a, Minecraft 16w35a, Minecraft 16w38a, Minecraft 16w39b, Minecraft 16w41a, Minecraft 16w42a, Minecraft 16w43a, Minecraft 16w44a, Minecraft 1.11.2, Minecraft 1.12 Pre-Release 6, Minecraft 1.12.1, Minecraft 1.12.2, Minecraft 18w06a, Minecraft 1.13.1, 19w41a, 19w46b, 1.15.1, 20w06a, 20w07a, 1.16.1, 20w28a
Fix Version/s: 1.16 Pre-release 3
You can grow jungle and oak sapling with certain blocks above or around it. It will not remove the them but it will replace the sapling with the log and create leafs.
Video demonstrating the issue: http://www.youtube.com/watch?v=eSZwNo37FQY
The following is based on a decompiled version of Minecraft 1.10 using MCP 9.30.
The reason for this is that the method net.minecraft.world.gen.feature.WorldGenAbstractTree.canGrowInto(Block) allows a tree to generate even if one of the following blocks is in the way:
|Block / Material 1||Gets replaced|
1 Multiple blocks can be out of the same material. For example "leaves" includes the blocks "leaves" and "leaves2"
Basically all blocks or materials with should be removed. Even though for logs it sounds reasonable having a oak tree with a single jungle log in the middle is pretty strange.