Program: 6610
Project: 6610
Buggy source:
public boolean tryInvPush(Block invBlock,Block startBlock,BlockFace forward,Material[] materials,int amount){
  Inventory inventory;
  BlockState state=invBlock.getState();
  if (state instanceof ContainerBlock)   inventory=((ContainerBlock)state).getInventory();
 else   return debugFail("String_Node_Str" + invBlock.getType().toString());
  Material putMaterial=null;
  ItemStack[] items=inventory.getContents();
  for (  Material material : materials) {
    int count=0;
    for (    ItemStack itemStack : items) {
      if (!itemStack.getType().equals(material))       continue;
      count+=itemStack.getAmount();
    }
    if (count >= amount) {
      putMaterial=material;
      break;
    }
  }
  if (putMaterial == null)   return debugFail("String_Node_Str");
  BlockLineIterator line=blocksInLine(startBlock,forward);
  for (int x=amount; x > 0; x--) {
    if (isEmpty(line.next()))     continue;
    if (!tryPushBlocks(line.currentBlock,forward,materials,x))     return debugFail("String_Node_Str");
    break;
  }
  line=blocksInLine(startBlock,forward);
  for (int i=0; i < items.length; i++) {
    ItemStack itemStack=items[i];
    if (!itemStack.getType().equals(putMaterial))     continue;
    int iAmount=itemStack.getAmount();
    int howMany;
    if (amount <= iAmount)     howMany=amount;
 else     howMany=iAmount;
    amount-=howMany;
    if (iAmount == howMany) {
      inventory.setItem(i,null);
    }
 else {
      itemStack.setAmount(iAmount - howMany);
      inventory.setItem(i,itemStack);
    }
    for (int j=0; j < howMany; j++)     line.next().setTypeIdAndData(itemStack.getTypeId(),(byte)itemStack.getDurability(),true);
  }
  return true;
}

Fixed version (ground truth):
public boolean tryInvPush(Block invBlock,Block startBlock,BlockFace forward,Material[] materials,int amount){
  Inventory inventory;
  BlockState state=invBlock.getState();
  if (state instanceof ContainerBlock)   inventory=((ContainerBlock)state).getInventory();
 else   return debugFail("String_Node_Str" + invBlock.getType().toString());
  Material putMaterial=null;
  ItemStack[] items=inventory.getContents();
  for (  Material material : materials) {
    int count=0;
    for (    ItemStack itemStack : items) {
      if (itemStack == null || !itemStack.getType().equals(material))       continue;
      count+=itemStack.getAmount();
    }
    if (count >= amount) {
      putMaterial=material;
      break;
    }
  }
  if (putMaterial == null)   return debugFail("String_Node_Str");
  BlockLineIterator line=blocksInLine(startBlock,forward);
  for (int x=amount; x > 0; x--) {
    if (isEmpty(line.next()))     continue;
    if (!tryPushBlocks(line.currentBlock,forward,materials,x))     return debugFail("String_Node_Str");
    break;
  }
  line=blocksInLine(startBlock,forward);
  for (int i=0; i < items.length; i++) {
    ItemStack itemStack=items[i];
    if (itemStack == null || !itemStack.getType().equals(putMaterial))     continue;
    int iAmount=itemStack.getAmount();
    int howMany;
    if (amount <= iAmount)     howMany=amount;
 else     howMany=iAmount;
    amount-=howMany;
    if (iAmount == howMany) {
      inventory.setItem(i,null);
    }
 else {
      itemStack.setAmount(iAmount - howMany);
      inventory.setItem(i,itemStack);
    }
    for (int j=0; j < howMany; j++)     line.next().setTypeIdAndData(itemStack.getTypeId(),(byte)itemStack.getDurability(),true);
  }
  return true;
}