SPIGOT-4160: StructureGrowEvent not triggering for giant trees

By: md_5 <git@md-5.net>

paper-server/nms-patches/WorldGenMegaTreeProvider.patch

@@ -0,0 +1,26 @@
+--- a/net/minecraft/server/WorldGenMegaTreeProvider.java
++++ b/net/minecraft/server/WorldGenMegaTreeProvider.java
+@@ -2,6 +2,7 @@
+ 
+ import java.util.Random;
+ import javax.annotation.Nullable;
++import org.bukkit.TreeType; // CraftBukkit
+ 
+ public abstract class WorldGenMegaTreeProvider extends WorldGenTreeProvider {
+ 
+@@ -28,6 +29,15 @@
+         if (worldgentreeabstract == null) {
+             return false;
+         } else {
++            // CraftBukkit start
++            if (worldgentreeabstract instanceof WorldGenJungleTree) {
++                BlockSapling.treeType = TreeType.JUNGLE;
++            } else if (worldgentreeabstract instanceof WorldGenMegaTree) {
++                BlockSapling.treeType = TreeType.MEGA_REDWOOD;
++            } else {
++                throw new IllegalArgumentException("Unknown tree generator " + worldgentreeabstract);
++            }
++            // CraftBukkit end
+             IBlockData iblockdata1 = Blocks.AIR.getBlockData();
+ 
+             generatoraccess.setTypeAndData(blockposition.a(i, 0, j), iblockdata1, 4);

paper-server/nms-patches/WorldGenTreeProvider.patch

@@ -8,7 +8,7 @@
  
  public abstract class WorldGenTreeProvider {
  
-@@ -16,6 +17,29 @@
+@@ -16,6 +17,25 @@
          if (worldgentreeabstract == null) {
              return false;
          } else {
@@ -21,10 +21,6 @@
 +                BlockSapling.treeType = TreeType.BIRCH;
 +            } else if (worldgentreeabstract instanceof WorldGenForestTree) {
 +                BlockSapling.treeType = TreeType.DARK_OAK;
-+            } else if (worldgentreeabstract instanceof WorldGenJungleTree) {
-+                BlockSapling.treeType = TreeType.JUNGLE;
-+            } else if (worldgentreeabstract instanceof WorldGenMegaTree) {
-+                BlockSapling.treeType = TreeType.MEGA_REDWOOD;
 +            } else if (worldgentreeabstract instanceof WorldGenTaiga1) {
 +                BlockSapling.treeType = TreeType.REDWOOD;
 +            } else if (worldgentreeabstract instanceof WorldGenTaiga2) {