Iron golems produce walking particles for light blocks

Can confirm in 21w17a.

Can confirm in 1.17 pre-release 3

Can confirm in 1.17.

Can confirm in 1.17.1.

I can confirm this behavior in 1.18. Here's a code analysis of this issue.

Code Analysis:

The following is based on a decompiled version of Minecraft 1.19.2 using MCP-Reborn.

net.minecraft.world.entity.animal.IronGolem.java

public class IronGolem extends AbstractGolem implements NeutralMob {
   ...
   public void aiStep() {
      super.aiStep();
      ...
      if (this.getDeltaMovement().horizontalDistanceSqr() > (double)2.5000003E-7F && this.random.nextInt(5) == 0) {
         int i = Mth.floor(this.getX());
         int j = Mth.floor(this.getY() - (double)0.2F);
         int k = Mth.floor(this.getZ());
         BlockState blockstate = this.level.getBlockState(new BlockPos(i, j, k));
         if (!blockstate.isAir()) {
            this.level.addParticle(new BlockParticleOption(ParticleTypes.BLOCK, blockstate), this.getX() + ((double)this.random.nextFloat() - 0.5D) * (double)this.getBbWidth(), this.getY() + 0.1D, this.getZ() + ((double)this.random.nextFloat() - 0.5D) * (double)this.getBbWidth(), 4.0D * ((double)this.random.nextFloat() - 0.5D), 0.5D, ((double)this.random.nextFloat() - 0.5D) * 4.0D);
         }
      }
      ...

If we look at the above class, we can see that there is only one necessary check that is carried out before allowing an iron golem to produce walking particles. This check is to see if the block below them is air, and if it is, walking particles won't be produced, but if it isn't, walking particles based on the block that the iron golem is standing on will be produced. The game doesn't check the RenderShape of the block that the iron golem standing on before allowing it to produce walking particles, therefore resulting in this problem occurring.

Fix:

Simply changing some lines of code to check the RenderShape of the block that the iron golem is standing on before allowing it to produce walking particles, will resolve this problem.

Current Code:

...
BlockState blockstate = this.level.getBlockState(new BlockPos(i, j, k));
if (!blockstate.isAir()) {
...

Fixed Code:

...
BlockPos blockpos = new BlockPos(i, j, k);
BlockState blockstate = this.level.getBlockState(blockpos);
if (blockstate.getRenderShape() != RenderShape.INVISIBLE) {
...

Can confirm in 1.18.1.

Can confirm in 1.18.2 and 22w14a.

Can confirm in 1.19.

Can confirm in 1.19.2.