CryptoCats Test Contract 2 — Verification

Contract Details

Field	Value
Address	0x78eea094e1d30141ccade64f8d29a7bfcc921f9e
Network	Ethereum Mainnet
Deploy Block	4532036
Deploy Date	2017-11-11
Runtime Size	8451 bytes

What Is This?

This is the second pre-launch test contract for CryptoCats, deployed the same day as Test Contract 1 but a few hours later (block 4532036 vs 4530388).

The key evolutionary step between T1 and T2:

• Struct field order changed to {bool isForSale; uint catIndex; address seller; string catName;} (v3-style)
• getCatDetail() return order changed to (bool, uint, address, string) — matching final v3
• allInitialOwnersAssigned() at runtime only sets allCatsAssigned=true — the 12-cat init block moved to the constructor
• seller field uses 0x0 instead of msg.sender
• imageHash was a placeholder: "INSERT ACTUAL HASH HERE"
• Compiled WITHOUT the optimizer — producing 8451 bytes vs 5823 for T1

Verification Result

Status: near_exact_match

	Bytes
Reconstructed	8137
On-chain	8451
Match	96.3%

What Matches

• ✅ All function selectors (identical)
• ✅ All function logic (identical structure)
• ✅ Struct layout confirmed: {bool isForSale; uint catIndex; address seller; string catName;}
• ✅ getCatDetail() return order confirmed: (bool isForSale, uint _catIndex, address seller, string catName)
• ✅ allInitialOwnersAssigned() runtime path: only sets allCatsAssigned=true

The 314-byte Gap

The 314-byte difference is dead code from the constructor-only internal cat initialization block. At runtime, allInitialOwnersAssigned() only sets allCatsAssigned=true — but the bytecode still contains the full 12-cat initialization logic as an unreachable code region preserved from the constructor path.

This is the same root cause as Test Contract 1 (108-byte gap), but larger because the optimizer is disabled. Without the optimizer, all that inline struct-assignment code is preserved verbatim rather than being compacted.

Compilation

# Requires Solidity 0.4.18, NO optimizer
"/Users/claw/Library/Application Support/svm/0.4.18/solc-0.4.18" --bin-runtime CryptoCatsMarket.sol

The absence of the optimizer preamble (63ffffffff7c) in the bytecode confirms no optimizer was used.

Key Differences from Test Contract 1

Feature	T1 (0xD23A)	T2 (0x78ee)
Optimizer	ON	OFF
Runtime size	5823 bytes	8451 bytes
Struct field order	{bool, address, string, uint}	{bool, uint, address, string}
getCatDetail returns	(uint, bool, address, string)	(bool, uint, address, string)
seller in allInitialOwnersAssigned	msg.sender	0x0
Cat init at runtime	Yes (in allInitialOwnersAssigned)	No (only allCatsAssigned=true)
imageHash	Real SHA-256 hash	"INSERT ACTUAL HASH HERE"
Dead code gap	108 bytes	314 bytes

Related Contracts

Contract	Description
0xD23AdE68C693264Aa9e8f8303F912A3E54718456	Test Contract 1 (same date, 5823 bytes, optimizer ON)
0x088C6Ad962812b5Aa905BA6F3c5c145f9D4C079f	CryptoCats v3 (production, Solidity 0.4.19, Etherscan verified)

Attribution

Bytecode archaeology by EthereumHistory.com
Part of the awesome-ethereum-proofs collection.