Paper/nms-patches/WorldGenTreeProvider.patch

--- a/net/minecraft/server/WorldGenTreeProvider.java
+++ b/net/minecraft/server/WorldGenTreeProvider.java
@@ -2,6 +2,7 @@
 
 import java.util.Random;
 import javax.annotation.Nullable;
+import org.bukkit.TreeType; // CraftBukkit
 
 public abstract class WorldGenTreeProvider {
 
@@ -16,6 +17,7 @@
         if (worldgenfeatureconfigured == null) {
             return false;
         } else {
+            setTreeType(worldgenfeatureconfigured); // CraftBukkit
             generatoraccess.setTypeAndData(blockposition, Blocks.AIR.getBlockData(), 4);
             ((WorldGenFeatureSmallTreeConfigurationConfiguration) worldgenfeatureconfigured.c).a();
             if (worldgenfeatureconfigured.a(generatoraccess, chunkgenerator, random, blockposition)) {
@@ -26,4 +28,46 @@
             }
         }
     }
+
+    // CraftBukkit start
+    protected void setTreeType(WorldGenFeatureConfigured<?, ?> worldgentreeabstract) {
+        if (worldgentreeabstract.c == BiomeDecoratorGroups.NORMAL_TREE) {
+            BlockSapling.treeType = TreeType.TREE;
+        } else if (worldgentreeabstract.c == BiomeDecoratorGroups.HUGE_RED_MUSHROOM) {
+            BlockSapling.treeType = TreeType.RED_MUSHROOM;
+        } else if (worldgentreeabstract.c == BiomeDecoratorGroups.HUGE_BROWN_MUSHROOM) {
+            BlockSapling.treeType = TreeType.BROWN_MUSHROOM;
+        } else if (worldgentreeabstract.c == BiomeDecoratorGroups.JUNGLE_TREE) {
+            BlockSapling.treeType = TreeType.COCOA_TREE;
+        } else if (worldgentreeabstract.c == BiomeDecoratorGroups.JUNGLE_TREE_NOVINE) {
+            BlockSapling.treeType = TreeType.SMALL_JUNGLE;
+        } else if (worldgentreeabstract.c == BiomeDecoratorGroups.PINE_TREE) {
+            BlockSapling.treeType = TreeType.TALL_REDWOOD;
+        } else if (worldgentreeabstract.c == BiomeDecoratorGroups.SPRUCE_TREE) {
+            BlockSapling.treeType = TreeType.REDWOOD;
+        } else if (worldgentreeabstract.c == BiomeDecoratorGroups.ACACIA_TREE) {
+            BlockSapling.treeType = TreeType.ACACIA;
+        } else if (worldgentreeabstract.c == BiomeDecoratorGroups.BIRCH_TREE) {
+            BlockSapling.treeType = TreeType.BIRCH;
+        } else if (worldgentreeabstract.c == BiomeDecoratorGroups.TALL_BIRCH_TREE) {
+            BlockSapling.treeType = TreeType.TALL_BIRCH;
+        } else if (worldgentreeabstract.c == BiomeDecoratorGroups.SWAMP_TREE) {
+            BlockSapling.treeType = TreeType.SWAMP;
+        } else if (worldgentreeabstract.c == BiomeDecoratorGroups.FANCY_TREE) {
+            BlockSapling.treeType = TreeType.BIG_TREE;
+        } else if (worldgentreeabstract.c == BiomeDecoratorGroups.JUNGLE_BUSH) {
+            BlockSapling.treeType = TreeType.JUNGLE_BUSH;
+        } else if (worldgentreeabstract.c == BiomeDecoratorGroups.DARK_OAK_TREE) {
+            BlockSapling.treeType = TreeType.DARK_OAK;
+        } else if (worldgentreeabstract.c == BiomeDecoratorGroups.MEGA_SPRUCE_TREE) {
+            BlockSapling.treeType = TreeType.MEGA_REDWOOD;
+        } else if (worldgentreeabstract.c == BiomeDecoratorGroups.MEGA_PINE_TREE) {
+            BlockSapling.treeType = TreeType.MEGA_REDWOOD;
+        } else if (worldgentreeabstract.c == BiomeDecoratorGroups.MEGA_JUNGLE_TREE) {
+            BlockSapling.treeType = TreeType.JUNGLE;
+        } else {
+            throw new IllegalArgumentException("Unknown tree generator " + worldgentreeabstract);
+        }
+    }
+    // CraftBukkit end
 }