From 64704c456fffb6043671692e65486f6daf529d58 Mon Sep 17 00:00:00 2001
From: Wei Tang <accounts@that.world>
Date: Tue, 15 Jan 2019 10:21:44 +0100
Subject: [PATCH] Handle the case for contract creation on an empty but exist
 account with storage items (#10065)

* Add is_base_storage_root_unchanged

* Fix compile, use a shortcut for check, and remove ignored tests

* Add a warn!

* Update ethereum/tests to v6.0.0-beta.2

* grumble: use {:#x} instead of 0x{:x}

Co-Authored-By: sorpaas <accounts@that.world>
---
 ethcore/res/ethereum/tests                    |  2 +-
 .../res/ethereum/tests-issues/currents.json   | 44 ++-----------------
 ethcore/src/externalities.rs                  |  7 ++-
 ethcore/src/state/account.rs                  |  5 +++
 ethcore/src/state/mod.rs                      |  7 +++
 5 files changed, 22 insertions(+), 43 deletions(-)

diff --git a/ethcore/res/ethereum/tests b/ethcore/res/ethereum/tests
index 2cd62aeec..420f44347 160000
--- a/ethcore/res/ethereum/tests
+++ b/ethcore/res/ethereum/tests
@@ -1 +1 @@
-Subproject commit 2cd62aeec11da29766b30d500f2b9a96f1f28cf0
+Subproject commit 420f443477caa8516f1f9ee8122fafc3415c0f34
diff --git a/ethcore/res/ethereum/tests-issues/currents.json b/ethcore/res/ethereum/tests-issues/currents.json
index 2ece034d0..d4d3f5e3a 100644
--- a/ethcore/res/ethereum/tests-issues/currents.json
+++ b/ethcore/res/ethereum/tests-issues/currents.json
@@ -1,42 +1,4 @@
-{ "block":
-	[
-		{
-			"reference": "None",
-			"comment": "This failing test is deemed skippable. Could not happen on a mainnet.",
-			"failing": "GeneralStateTest_stCreate2",
-			"subtests": ["RevertInCreateInInitCreate2_d0g0v0_Constantinople"]
-		},
-		{
-			"reference": "None",
-			"comment": "This failing test is deemed skippable. Could not happen on a mainnet.",
-			"failing": "GeneralStateTest_stRevertTest",
-			"subtests": ["RevertInCreateInInit_d0g0v0_Constantinople"]
-		}
-	],
-	"state":
-	[
-		{
-			"reference": "None",
-			"comment": "This failing test is deemed skippable. Could not happen on a mainnet.",
-			"failing": "stCreate2Test",
-			"subtests": {
-				"RevertInCreateInInitCreate2": {
-					"subnumbers": ["1"],
-					"chain": "Constantinople (test)"
-				}
-			}
-		},
-		{
-			"reference": "None",
-			"comment": "This failing test is deemed skippable. Could not happen on a mainnet.",
-			"failing": "stRevertTest",
-			"subtests": {
-				"RevertInCreateInInit": {
-					"subnumbers": ["1"],
-					"chain": "Constantinople (test)"
-				}
-			}
-		}
-		
-	]
+{
+	"block": [],
+	"state": []
 }
diff --git a/ethcore/src/externalities.rs b/ethcore/src/externalities.rs
index 0cda8ac87..a2f35b6de 100644
--- a/ethcore/src/externalities.rs
+++ b/ethcore/src/externalities.rs
@@ -116,7 +116,12 @@ impl<'a, T: 'a, V: 'a, B: 'a> Ext for Externalities<'a, T, V, B>
 	where T: Tracer, V: VMTracer, B: StateBackend
 {
 	fn initial_storage_at(&self, key: &H256) -> vm::Result<H256> {
-		self.state.checkpoint_storage_at(0, &self.origin_info.address, key).map(|v| v.unwrap_or(H256::zero())).map_err(Into::into)
+		if self.state.is_base_storage_root_unchanged(&self.origin_info.address)? {
+			self.state.checkpoint_storage_at(0, &self.origin_info.address, key).map(|v| v.unwrap_or(H256::zero())).map_err(Into::into)
+		} else {
+			warn!(target: "externalities", "Detected existing account {:#x} where a forced contract creation happened.", self.origin_info.address);
+			Ok(H256::zero())
+		}
 	}
 
 	fn storage_at(&self, key: &H256) -> vm::Result<H256> {
diff --git a/ethcore/src/state/account.rs b/ethcore/src/state/account.rs
index d4a42dd31..e4553b906 100644
--- a/ethcore/src/state/account.rs
+++ b/ethcore/src/state/account.rs
@@ -451,6 +451,11 @@ impl Account {
 		}
 	}
 
+	/// Whether the base storage root of this account is unchanged.
+	pub fn is_base_storage_root_unchanged(&self) -> bool {
+		self.original_storage_cache.is_none()
+	}
+
 	/// Storage root where the account changes are based upon.
 	pub fn base_storage_root(&self) -> H256 {
 		self.storage_root
diff --git a/ethcore/src/state/mod.rs b/ethcore/src/state/mod.rs
index 8a46c7e1d..2939c9729 100644
--- a/ethcore/src/state/mod.rs
+++ b/ethcore/src/state/mod.rs
@@ -539,6 +539,13 @@ impl<B: Backend> State<B> {
 			|a| a.as_ref().map_or(self.account_start_nonce, |account| *account.nonce()))
 	}
 
+	/// Whether the base storage root of an account remains unchanged.
+	pub fn is_base_storage_root_unchanged(&self, a: &Address) -> TrieResult<bool> {
+		Ok(self.ensure_cached(a, RequireCache::None, true,
+			|a| a.as_ref().map(|account| account.is_base_storage_root_unchanged()))?
+			.unwrap_or(true))
+	}
+
 	/// Get the storage root of account `a`.
 	pub fn storage_root(&self, a: &Address) -> TrieResult<Option<H256>> {
 		self.ensure_cached(a, RequireCache::None, true,