Provide a little more information on why things might fail.

alethzero/Transact.cpp

@@ -338,7 +338,7 @@ void Transact::rejigData()
 	}
 	if (er.codeDeposit == CodeDeposit::Failed)
 	{
-		bail("<div class=\"error\"><span class=\"icon\">ERROR</span> Code deposit failed due to insufficient gas</div>");
+		bail("<div class=\"error\"><span class=\"icon\">ERROR</span> Code deposit failed due to insufficient gas; " + QString::fromStdString(toString(er.gasForDeposit)) + " GAS &lt; " + QString::fromStdString(toString(er.depositSize)) + " bytes * " + QString::fromStdString(toString(c_createDataGas)) + "GAS/byte</div>");
 		return;
 	}
 

libethcore/Params.h

@@ -29,15 +29,15 @@ namespace eth
 {
 
 //--- BEGIN: AUTOGENERATED FROM /feeStructure.json
-extern u256 const c_genesisDifficulty;
-extern u256 const c_maximumExtraDataSize;
-extern u256 const c_epochDuration;
 extern u256 const c_genesisGasLimit;
 extern u256 const c_minGasLimit;
 extern u256 const c_gasLimitBoundDivisor;
+extern u256 const c_genesisDifficulty;
 extern u256 const c_minimumDifficulty;
 extern u256 const c_difficultyBoundDivisor;
 extern u256 const c_durationLimit;
+extern u256 const c_maximumExtraDataSize;
+extern u256 const c_epochDuration;
 extern u256 const c_stackLimit;
 
 extern u256 const c_tierStepGas[8];			///< Once per operation, for a selection of them.

libethereum/Executive.cpp

@@ -46,7 +46,7 @@ u256 Executive::gasUsed() const
 
 ExecutionResult Executive::executionResult() const
 {
-	return ExecutionResult(gasUsed(), m_excepted, m_newAddress, m_out, m_codeDeposit, m_ext ? m_ext->sub.refunds : 0);
+	return ExecutionResult(gasUsed(), m_excepted, m_newAddress, m_out, m_codeDeposit, m_ext ? m_ext->sub.refunds : 0, m_depositSize, m_gasForDeposit);
 }
 
 void Executive::accrueSubState(SubState& _parentContext)
@@ -221,6 +221,8 @@ bool Executive::go(OnOpFunc const& _onOp)
 
 			if (m_isCreation)
 			{
+				m_gasForDeposit = m_endGas;
+				m_depositSize = m_out.size();
 				if (m_out.size() * c_createDataGas <= m_endGas)
 				{
 					m_codeDeposit = CodeDeposit::Success;
@@ -228,6 +230,7 @@ bool Executive::go(OnOpFunc const& _onOp)
 				}
 				else
 				{
+
 					m_codeDeposit = CodeDeposit::Failed;
 					m_out.reset();
 				}

libethereum/Executive.h

@@ -128,6 +128,8 @@ private:
 
 	unsigned m_depth = 0;				///< The context's call-depth.
 	bool m_isCreation = false;			///< True if the transaction creates a contract, or if create() is called.
+	unsigned m_depositSize = 0;			///< Amount of code of the creation's attempted deposit.
+	u256 m_gasForDeposit;				///< Amount of gas remaining for the code deposit phase.
 	CodeDeposit m_codeDeposit = CodeDeposit::None;	///< True if an attempted deposit failed due to lack of gas.
 	TransactionException m_excepted = TransactionException::None;	///< Details if the VM's execution resulted in an exception.
 	u256 m_endGas;						///< The final amount of gas for the transaction.

libethereum/Transaction.cpp

@@ -88,12 +88,12 @@ Transaction::Transaction(bytesConstRef _rlpData, CheckSignature _checkSig)
 	}
 	catch (Exception& _e)
 	{
-		_e << errinfo_name("invalid transaction format") << BadFieldError(field,toHex(rlp[field].data().toBytes()));
+		_e << errinfo_name("invalid transaction format") << BadFieldError(field, toHex(rlp[field].data().toBytes()));
 		throw;
 	}
 }
 
-Address Transaction::safeSender() const noexcept
+Address const& Transaction::safeSender() const noexcept
 {
 	try
 	{
@@ -102,11 +102,11 @@ Address Transaction::safeSender() const noexcept
 	catch (...)
 	{
 		cwarn << "safeSender() did throw an exception: " <<  boost::current_exception_diagnostic_information();
-		return Address();
+		return NullAddress;
 	}
 }
 
-Address Transaction::sender() const
+Address const& Transaction::sender() const
 {
 	if (!m_sender)
 	{

libethereum/Transaction.h

@@ -75,17 +75,30 @@ TransactionException toTransactionException(VMException const& _e);
 struct ExecutionResult
 {
 	ExecutionResult() = default;
-	ExecutionResult(u256 _gasUsed, TransactionException _excepted, Address _newAddress, bytesConstRef _output, CodeDeposit _codeDeposit, u256 _gasRefund): gasUsed(_gasUsed), excepted(_excepted), newAddress(_newAddress), output(_output.toBytes()), codeDeposit(_codeDeposit), gasRefunded(_gasRefund) {}
+	ExecutionResult(u256 const& _gasUsed, TransactionException _excepted, Address const& _newAddress, bytesConstRef _output, CodeDeposit _codeDeposit, u256 const& _gasRefund, unsigned _depositSize, u256 const& _gasForDeposit):
+		gasUsed(_gasUsed),
+		excepted(_excepted),
+		newAddress(_newAddress),
+		output(_output.toBytes()),
+		codeDeposit(_codeDeposit),
+		gasRefunded(_gasRefund),
+		depositSize(_depositSize),
+		gasForDeposit(_gasForDeposit)
+	{}
 	u256 gasUsed = 0;
 	TransactionException excepted = TransactionException::Unknown;
 	Address newAddress;
 	bytes output;
 	CodeDeposit codeDeposit = CodeDeposit::None;
 	u256 gasRefunded = 0;
+	unsigned depositSize = 0;
+	u256 gasForDeposit;
 };
 
 std::ostream& operator<<(std::ostream& _out, ExecutionResult const& _er);
 
+static const Address NullAddress;
+
 /// Encodes a transaction, ready to be exported to or freshly imported from RLP.
 class Transaction
 {
@@ -94,16 +107,16 @@ public:
 	Transaction() {}
 
 	/// Constructs a signed message-call transaction.
-	Transaction(u256 _value, u256 _gasPrice, u256 _gas, Address const& _dest, bytes const& _data, u256 _nonce, Secret const& _secret): m_type(MessageCall), m_nonce(_nonce), m_value(_value), m_receiveAddress(_dest), m_gasPrice(_gasPrice), m_gas(_gas), m_data(_data) { sign(_secret); }
+	Transaction(u256 const& _value, u256 const& _gasPrice, u256 const& _gas, Address const& _dest, bytes const& _data, u256 const& _nonce, Secret const& _secret): m_type(MessageCall), m_nonce(_nonce), m_value(_value), m_receiveAddress(_dest), m_gasPrice(_gasPrice), m_gas(_gas), m_data(_data) { sign(_secret); }
 
 	/// Constructs a signed contract-creation transaction.
-	Transaction(u256 _value, u256 _gasPrice, u256 _gas, bytes const& _data, u256 _nonce, Secret const& _secret): m_type(ContractCreation), m_nonce(_nonce), m_value(_value), m_gasPrice(_gasPrice), m_gas(_gas), m_data(_data) { sign(_secret); }
+	Transaction(u256 const& _value, u256 const& _gasPrice, u256 const& _gas, bytes const& _data, u256 const& _nonce, Secret const& _secret): m_type(ContractCreation), m_nonce(_nonce), m_value(_value), m_gasPrice(_gasPrice), m_gas(_gas), m_data(_data) { sign(_secret); }
 
 	/// Constructs an unsigned message-call transaction.
-	Transaction(u256 _value, u256 _gasPrice, u256 _gas, Address const& _dest, bytes const& _data): m_type(MessageCall), m_value(_value), m_receiveAddress(_dest), m_gasPrice(_gasPrice), m_gas(_gas), m_data(_data) {}
+	Transaction(u256 const& _value, u256 const& _gasPrice, u256 const& _gas, Address const& _dest, bytes const& _data): m_type(MessageCall), m_value(_value), m_receiveAddress(_dest), m_gasPrice(_gasPrice), m_gas(_gas), m_data(_data) {}
 
 	/// Constructs an unsigned contract-creation transaction.
-	Transaction(u256 _value, u256 _gasPrice, u256 _gas, bytes const& _data): m_type(ContractCreation), m_value(_value), m_gasPrice(_gasPrice), m_gas(_gas), m_data(_data) {}
+	Transaction(u256 const& _value, u256 const& _gasPrice, u256 const& _gas, bytes const& _data): m_type(ContractCreation), m_value(_value), m_gasPrice(_gasPrice), m_gas(_gas), m_data(_data) {}
 
 	/// Constructs a transaction from the given RLP.
 	explicit Transaction(bytesConstRef _rlp, CheckSignature _checkSig);
@@ -118,9 +131,9 @@ public:
 	bool operator!=(Transaction const& _c) const { return !operator==(_c); }
 
 	/// @returns sender of the transaction from the signature (and hash).
-	Address sender() const;
+	Address const& sender() const;
 	/// Like sender() but will never throw. @returns a null Address if the signature is invalid.
-	Address safeSender() const noexcept;
+	Address const& safeSender() const noexcept;
 
 	/// @returns true if transaction is non-null.
 	explicit operator bool() const { return m_type != NullTransaction; }