Program: 81837
Project: 81837
Buggy source:
public static void profileForFoliageShader(){
  World world=Minecraft.getMinecraft().world;
  Entity entityIn=Minecraft.getMinecraft().player;
  BlockPos pos=entityIn.getPosition();
  boolean add=true;
  boolean trim=true;
  int radialRange=FoliageRenderer.radialRange;
  int xzRange=radialRange;
  int yRange=radialRange;
  Random rand=new Random();
  if (trim) {
    Iterator<Map.Entry<BlockPos,List<Foliage>>> it=ExtendedRenderer.foliageRenderer.lookupPosToFoliage.entrySet().iterator();
    while (it.hasNext()) {
      Map.Entry<BlockPos,List<Foliage>> entry=it.next();
      if (!validFoliageSpot(world,entry.getKey().down())) {
        it.remove();
        for (        Foliage entry2 : entry.getValue()) {
          markMeshDirty(entry2.particleTexture,true);
          ExtendedRenderer.foliageRenderer.getFoliageForSprite(entry2.particleTexture).remove(entry2);
        }
      }
 else       if (entityIn.getDistanceSq(entry.getKey()) > radialRange * radialRange) {
        it.remove();
        for (        Foliage entry2 : entry.getValue()) {
          markMeshDirty(entry2.particleTexture,true);
          ExtendedRenderer.foliageRenderer.getFoliageForSprite(entry2.particleTexture).remove(entry2);
        }
      }
    }
  }
  if (add) {
    for (int x=-xzRange; x <= xzRange; x++) {
      for (int z=-xzRange; z <= xzRange; z++) {
        for (int y=-yRange; y <= yRange; y++) {
          BlockPos posScan=pos.add(x,y,z);
          if (!ExtendedRenderer.foliageRenderer.lookupPosToFoliage.containsKey(posScan)) {
            if (validFoliageSpot(entityIn.world,posScan.down())) {
              if (entityIn.getDistanceSq(posScan) <= radialRange * radialRange) {
                TextureAtlasSprite sprite=ParticleRegistry.tallgrass;
                ExtendedRenderer.foliageRenderer.addForPos(sprite,posScan);
                markMeshDirty(sprite,true);
              }
            }
          }
 else {
          }
        }
      }
    }
  }
  for (  Map.Entry<TextureAtlasSprite,List<Foliage>> entry : ExtendedRenderer.foliageRenderer.foliage.entrySet()) {
    InstancedMeshFoliage mesh=MeshBufferManagerFoliage.getMesh(entry.getKey());
    if (mesh.dirtyVBO2Flag) {
      updateVBO2Threaded(entry.getKey());
    }
  }
}

Fixed version (ground truth):
public static void profileForFoliageShader(){
  World world=Minecraft.getMinecraft().world;
  Entity entityIn=Minecraft.getMinecraft().player;
  BlockPos pos=entityIn.getPosition();
  boolean add=true;
  boolean trim=true;
  int radialRange=FoliageRenderer.radialRange;
  int xzRange=radialRange;
  int yRange=radialRange;
  Random rand=new Random();
  if (trim) {
    Iterator<Map.Entry<BlockPos,List<Foliage>>> it=ExtendedRenderer.foliageRenderer.lookupPosToFoliage.entrySet().iterator();
    while (it.hasNext()) {
      Map.Entry<BlockPos,List<Foliage>> entry=it.next();
      if (!validFoliageSpot(world,entry.getKey().down())) {
        it.remove();
        for (        Foliage entry2 : entry.getValue()) {
          markMeshDirty(entry2.particleTexture,true);
          ExtendedRenderer.foliageRenderer.getFoliageForSprite(entry2.particleTexture).remove(entry2);
        }
      }
 else       if (entityIn.getDistanceSq(entry.getKey()) > radialRange * radialRange) {
        it.remove();
        for (        Foliage entry2 : entry.getValue()) {
          markMeshDirty(entry2.particleTexture,true);
          ExtendedRenderer.foliageRenderer.getFoliageForSprite(entry2.particleTexture).remove(entry2);
        }
      }
    }
  }
  if (add) {
    for (int x=-xzRange; x <= xzRange; x++) {
      for (int z=-xzRange; z <= xzRange; z++) {
        for (int y=-yRange; y <= yRange; y++) {
          BlockPos posScan=pos.add(x,y,z);
          if (!ExtendedRenderer.foliageRenderer.lookupPosToFoliage.containsKey(posScan)) {
            if (validFoliageSpot(entityIn.world,posScan.down())) {
              if (entityIn.getDistanceSq(posScan) <= radialRange * radialRange) {
                ExtendedRenderer.foliageRenderer.addForPosSeaweed(posScan);
                for (                TextureAtlasSprite sprite : ParticleRegistry.listSeaweed) {
                  markMeshDirty(sprite,true);
                }
              }
            }
          }
 else {
          }
        }
      }
    }
  }
  Foliage.interpPosXThread=entityIn.posX;
  Foliage.interpPosYThread=entityIn.posY;
  Foliage.interpPosZThread=entityIn.posZ;
  for (  Map.Entry<TextureAtlasSprite,List<Foliage>> entry : ExtendedRenderer.foliageRenderer.foliage.entrySet()) {
    InstancedMeshFoliage mesh=MeshBufferManagerFoliage.getMesh(entry.getKey());
    if (mesh.dirtyVBO2Flag) {
      updateVBO2Threaded(entry.getKey());
    }
  }
}