add tag for non-harvestable blocks

src/generated/resources/data/create/tags/blocks/not_harvestable.json

@@ -0,0 +1,5 @@
+{
+  "values": [
+    "minecraft:fire"
+  ]
+}

src/main/java/com/simibubi/create/AllTags.java

@@ -113,6 +113,7 @@ public class AllTags {
 		FALLBACK_MOUNTED_STORAGE_BLACKLIST,
 		ROOTS,
 		SUGAR_CANE_VARIANTS,
+		NOT_HARVESTABLE,
 
 		CORALS,
 

src/main/java/com/simibubi/create/content/contraptions/actors/harvester/HarvesterMovementBehaviour.java

@@ -57,12 +57,15 @@ public class HarvesterMovementBehaviour implements MovementBehaviour {
 	@Override
 	public void visitNewPosition(MovementContext context, BlockPos pos) {
 		Level world = context.world;
-		BlockState stateVisited = world.getBlockState(pos);
-		boolean notCropButCuttable = false;
-
 		if (world.isClientSide)
 			return;
 
+		BlockState stateVisited = world.getBlockState(pos);
+		if (stateVisited.isAir() || AllBlockTags.NOT_HARVESTABLE.matches(stateVisited))
+			return;
+
+		boolean notCropButCuttable = false;
+
 		if (!isValidCrop(world, pos, stateVisited)) {
 			if (isValidOther(world, pos, stateVisited))
 				notCropButCuttable = true;

src/main/java/com/simibubi/create/infrastructure/data/CreateRegistrateTags.java

@@ -127,6 +127,9 @@ public class CreateRegistrateTags {
 		prov.tag(AllBlockTags.SUGAR_CANE_VARIANTS.tag)
 			.add(Blocks.SUGAR_CANE);
 
+		prov.tag(AllBlockTags.NOT_HARVESTABLE.tag)
+				.add(Blocks.FIRE);
+
 		prov.tag(AllBlockTags.CORALS.tag)
 			.add(Blocks.DEAD_TUBE_CORAL, Blocks.DEAD_BRAIN_CORAL, Blocks.DEAD_BUBBLE_CORAL, Blocks.DEAD_FIRE_CORAL,
 				Blocks.DEAD_HORN_CORAL, Blocks.TUBE_CORAL, Blocks.BRAIN_CORAL, Blocks.BUBBLE_CORAL,