Program: 31454
Project: 31454
Buggy source:
@Nonnull public String getUniqueIdentifierForStack(@Nonnull ItemStack stack,@Nonnull UidMode mode){
  if (uidCacheEnabled) {
    String result=uidCache.get(mode).get(stack);
    if (result != null) {
      return result;
    }
  }
  Item item=stack.getItem();
  if (item == null) {
    throw new NullPointerException(nullItemInStack);
  }
  ResourceLocation itemName=item.getRegistryName();
  if (itemName == null) {
    String stackInfo=ErrorUtil.getItemStackInfo(stack);
    throw new NullPointerException("String_Node_Str" + stackInfo);
  }
  StringBuilder itemKey=new StringBuilder(itemName.toString());
  ISubtypeRegistry subtypeRegistry=Internal.getHelpers().getSubtypeRegistry();
  String subtypeInfo=subtypeRegistry.getSubtypeInfo(stack);
  if (subtypeInfo != null) {
    itemKey.append(':').append(subtypeInfo);
  }
  int metadata=stack.getMetadata();
  if (mode == UidMode.WILDCARD || metadata == OreDictionary.WILDCARD_VALUE) {
    return itemKey.toString();
  }
  if (mode == UidMode.FULL) {
    itemKey.append(':').append(metadata);
    NBTTagCompound serializedNbt=stack.serializeNBT();
    NBTTagCompound nbtTagCompound=serializedNbt.getCompoundTag("String_Node_Str");
    if (serializedNbt.hasKey("String_Node_Str")) {
      if (nbtTagCompound == null) {
        nbtTagCompound=new NBTTagCompound();
      }
      NBTTagCompound forgeCaps=serializedNbt.getCompoundTag("String_Node_Str");
      if (!forgeCaps.hasNoTags()) {
        nbtTagCompound.setTag("String_Node_Str",forgeCaps);
      }
    }
    if (nbtTagCompound != null && !nbtTagCompound.hasNoTags()) {
      itemKey.append(':').append(nbtTagCompound);
    }
  }
 else   if (stack.getHasSubtypes()) {
    itemKey.append(':').append(metadata);
  }
  String result=itemKey.toString();
  if (uidCacheEnabled) {
    uidCache.get(mode).put(stack,result);
  }
  return result;
}

Fixed version (ground truth):
@Nonnull public String getUniqueIdentifierForStack(@Nonnull ItemStack stack,@Nonnull UidMode mode){
  if (uidCacheEnabled) {
    String result=uidCache.get(mode).get(stack);
    if (result != null) {
      return result;
    }
  }
  Item item=stack.getItem();
  if (item == null) {
    throw new NullPointerException(nullItemInStack);
  }
  ResourceLocation itemName=item.getRegistryName();
  if (itemName == null) {
    String stackInfo=ErrorUtil.getItemStackInfo(stack);
    throw new NullPointerException("String_Node_Str" + stackInfo);
  }
  StringBuilder itemKey=new StringBuilder(itemName.toString());
  ISubtypeRegistry subtypeRegistry=Internal.getHelpers().getSubtypeRegistry();
  String subtypeInfo=subtypeRegistry.getSubtypeInfo(stack);
  if (subtypeInfo != null) {
    itemKey.append(':').append(subtypeInfo);
  }
  int metadata=stack.getMetadata();
  if (mode == UidMode.WILDCARD || metadata == OreDictionary.WILDCARD_VALUE) {
    return itemKey.toString();
  }
  if (mode == UidMode.FULL) {
    itemKey.append(':').append(metadata);
    NBTTagCompound serializedNbt=stack.serializeNBT();
    NBTTagCompound nbtTagCompound=serializedNbt.getCompoundTag("String_Node_Str").copy();
    if (serializedNbt.hasKey("String_Node_Str")) {
      if (nbtTagCompound == null) {
        nbtTagCompound=new NBTTagCompound();
      }
      NBTTagCompound forgeCaps=serializedNbt.getCompoundTag("String_Node_Str");
      if (!forgeCaps.hasNoTags()) {
        nbtTagCompound.setTag("String_Node_Str",forgeCaps);
      }
    }
    if (nbtTagCompound != null && !nbtTagCompound.hasNoTags()) {
      itemKey.append(':').append(nbtTagCompound);
    }
  }
 else   if (stack.getHasSubtypes()) {
    itemKey.append(':').append(metadata);
  }
  String result=itemKey.toString();
  if (uidCacheEnabled) {
    uidCache.get(mode).put(stack,result);
  }
  return result;
}