"Estimated fee consuption: The contract won't allow this transaction to be executed." happening in my custom contract in my private network

Question

Any ideas?

My contract:

pragma solidity ^0.4.0;
contract shares {

    enum OrderType{BUY,SELL}

    struct Order{
        address solicitant;
        uint price;
        uint quantity;
    }
    Order[] internal buyList;
    Order[] internal sellList;
    Order auxiliary;
    mapping (address=>uint) public balanceOf;
    uint sharePrice;

    function shares(uint initialSupply){
        balanceOf[msg.sender]=initialSupply;
    }

    function insertBuyOrder(uint proposedPrice, uint quantity){
        if(msg.sender.balance<quantity*proposedPrice) throw;
        insert(Order(msg.sender,proposedPrice,quantity), OrderType.BUY);
        resolveBuyMatches();
    }

    function resolveBuyMatches() internal{
        if(sellList.length>0 && getBiggestBuyOrder().price>=getSmallestSellOrder().price){
            if(getBiggestBuyOrder().quantity>=getSmallestSellOrder().quantity){    
                transferShares(getSmallestSellOrder().solicitant,getBiggestBuyOrder().solicitant,getSmallestSellOrder().quantity);
                remove(OrderType.SELL);
                getBiggestBuyOrder().quantity-=getSmallestSellOrder().quantity;
                if(getBiggestBuyOrder().quantity==0) remove(OrderType.BUY);
                else resolveBuyMatches();
            }
            else {
                transferShares(getSmallestSellOrder().solicitant,getBiggestBuyOrder().solicitant,getBiggestBuyOrder().quantity);
                remove(OrderType.BUY);
                getSmallestSellOrder().quantity-=getBiggestBuyOrder().quantity;
            }
        }
    }

    function insertSellOrder(uint proposedPrice, uint quantity){
        if(balanceOf[msg.sender]<quantity) throw;
        insert(Order(msg.sender,proposedPrice,quantity), OrderType.SELL);
        resolveSellMatches();
    }

    function resolveSellMatches() internal{
        if(buyList.length>0 && getBiggestBuyOrder().price>=getSmallestSellOrder().price){
            if(getBiggestBuyOrder().quantity>=getSmallestSellOrder().quantity){    
                transferShares(getSmallestSellOrder().solicitant,getBiggestBuyOrder().solicitant,getSmallestSellOrder().quantity);
                remove(OrderType.SELL);
                getBiggestBuyOrder().quantity-=getSmallestSellOrder().quantity;
                if(getBiggestBuyOrder().quantity==0) remove(OrderType.BUY);
            }
            else {
                transferShares(getSmallestSellOrder().solicitant,getBiggestBuyOrder().solicitant,getBiggestBuyOrder().quantity);
                remove(OrderType.BUY);
                getSmallestSellOrder().quantity-=getBiggestBuyOrder().quantity;
                resolveSellMatches();
            }
        }
    }

    function transferShares(address from, address to, uint quantity){
        if(balanceOf[from]<quantity) throw;
        balanceOf[from]-=quantity;
        balanceOf[to]+=quantity;
    }

    function getSmallestSellOrder() internal returns (Order smallestSellOrder){
        smallestSellOrder = sellList[0];
    }

    function getBiggestBuyOrder() internal returns (Order biggestBuyOrder){
        biggestBuyOrder = buyList[0];
    }

    function remove(OrderType orderType) internal
    {
        Order[] orderList = buyList;
        if(orderType==OrderType.SELL) orderList = sellList;
        orderList[0]=orderList[orderList.length-1];
        orderList.length--;
        reorderAfterRemove(orderList,0);
    }
    function reorderAfterRemove(Order[] orderList,uint relocatingNodeIndex) internal
    {
        uint smallestChildIndex = relocatingNodeIndex*2;
        if(relocatingNodeIndex*2>=orderList.length) return;
        if(orderList[relocatingNodeIndex*2+1].quantity<orderList[relocatingNodeIndex*2].quantity) smallestChildIndex=(relocatingNodeIndex*2+1);
        if(orderList[smallestChildIndex].quantity<orderList[relocatingNodeIndex].quantity)
        {
            swap(orderList,relocatingNodeIndex,smallestChildIndex);
            relocatingNodeIndex=smallestChildIndex;
            reorderAfterRemove(orderList, relocatingNodeIndex);
        }
    }   
    function insert(Order newOrder, OrderType orderType) internal{
        Order[] orderList = buyList;
        if(orderType==OrderType.SELL) orderList = sellList; 
        uint length = orderList.length;
        buyList.push(newOrder);
        orderList.length++;
        reorderAfterInsert(orderList,length/2, length);
    }

    function reorderAfterInsert(Order[] orderList, uint smallerIndex, uint biggerIndex) internal{
        if(biggerIndex>0 && orderList[smallerIndex].quantity>orderList[biggerIndex].quantity)
        {    
            swap(orderList,smallerIndex,biggerIndex);
            reorderAfterInsert(orderList,smallerIndex/2, smallerIndex);
        }
    }

    function swap(Order[] orderList, uint smallerIndex, uint biggerIndex) internal{
        auxiliary = orderList[smallerIndex];
        orderList[smallerIndex] = orderList[biggerIndex];
        orderList[biggerIndex] = auxiliary;
    }   
}

Answer 1

I debugged with Remix and found the problem. As I did it some days ago and my code has change considerably, I can't find which was precisely the mistake, but what I learnt is: debug with Remix! It even has a button to skip to the problem directly.