fix sweared plants drop on place nearby sweared plants

- it's more a dirty fix, but it actually works
- could be improved in the future

src/main/java/de/pilz/plantmegapackfix/PMPFixMixinLoaderLate.java

@@ -23,6 +23,8 @@ public List<String> getMixins(Set<String> loadedMods) {
         if (loadedMods.contains("plantmegapack")) {
             list.add("PMPGenVineMixin");
             list.add("PMPWorldGeneratorMixin");
+            list.add("PMPGenAquaticMixin");
+            list.add("PMPBlockPlantMixin");
         }
 
         return list;

src/main/java/de/pilz/plantmegapackfix/mixins/late/PMPBlockPlantMixin.java

@@ -0,0 +1,29 @@
+package de.pilz.plantmegapackfix.mixins.late;
+
+import net.minecraft.block.Block;
+import net.minecraft.world.World;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+
+import com.llamalad7.mixinextras.injector.ModifyExpressionValue;
+import com.llamalad7.mixinextras.sugar.Local;
+
+import plantmegapack.block.PMPBlockPlant;
+import plantmegapack.common.PMPPlantGrowthType;
+
+@Mixin(PMPBlockPlant.class)
+public abstract class PMPBlockPlantMixin {
+
+    @ModifyExpressionValue(
+        method = "onNeighborBlockChange",
+        at = @At(
+            value = "INVOKE",
+            target = "Lplantmegapack/block/PMPBlockPlant;canBlockStay(Lnet/minecraft/world/World;III)Z"),
+        remap = false)
+    private boolean pmpfix$onNeighborBlockChange$ignoreSweared(boolean original, World world, int x, int y, int z,
+        @Local Block block) {
+        return original || (block instanceof PMPBlockPlant
+            && ((PMPBlockPlant) block).plantData.attributes.growthType == PMPPlantGrowthType.SEAWEED);
+    }
+}

src/main/java/de/pilz/plantmegapackfix/mixins/late/PMPGenAquaticMixin.java

@@ -0,0 +1,27 @@
+package de.pilz.plantmegapackfix.mixins.late;
+
+import net.minecraft.block.Block;
+import net.minecraft.world.World;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+
+import com.llamalad7.mixinextras.injector.v2.WrapWithCondition;
+
+import plantmegapack.block.PMPBlockPlant;
+import plantmegapack.worldgen.PMPGenAquatic;
+
+@Mixin(PMPGenAquatic.class)
+public abstract class PMPGenAquaticMixin {
+
+    @WrapWithCondition(
+        method = "spawnRandomSeaweedCluster",
+        at = @At(value = "INVOKE", target = "Lnet/minecraft/world/World;setBlock(IIILnet/minecraft/block/Block;II)Z"),
+        remap = false)
+    private static boolean pmpfix$spawnRandomSeaweedCluster$checkForWaterAbove(World world, int x, int y, int z,
+        Block blockIn, int metadataIn, int flags) {
+        PMPBlockPlant plant = (PMPBlockPlant) blockIn;
+        if (!plant.canPlaceBlockAt(world, x, y, z)) return false;
+        return true;
+    }
+}

src/main/java/de/pilz/plantmegapackfix/mixins/late/PMPWorldGeneratorMixin.java

@@ -29,7 +29,7 @@ private void generateSurface(World world, Random random, int chunkX, int chunkZ)
     private void generateEnd(World world, Random random, int chunkX, int chunkZ) {}
 
     @Inject(method = "generate", at = @At("RETURN"), cancellable = false, remap = false)
-    private void pmpfix$$checkWorldProviderSuface(Random random, int chunkX, int chunkZ, World world,
+    private void pmpfix$generate$checkWorldProviderSuface(Random random, int chunkX, int chunkZ, World world,
         IChunkProvider chunkGenerator, IChunkProvider chunkProvider, CallbackInfo callback) {
         if (world.provider.dimensionId == 0 || world.provider.dimensionId == -1 || world.provider.dimensionId == 1) {
             // Handled by original already