From ce25ddfa6a9b8cfff08b4a05591dcc3b4a8b63cc Mon Sep 17 00:00:00 2001
From: chriseth <c@ethdev.com>
Date: Sun, 4 Oct 2015 11:05:57 +0200
Subject: [PATCH] Encode storage items correctly for library calls.

---
 libsolidity/CompilerUtils.cpp             |  9 +++++++-
 libsolidity/ExpressionCompiler.cpp        |  3 ++-
 test/libsolidity/SolidityEndToEndTest.cpp | 26 +++++++++++++++++++++++
 3 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/libsolidity/CompilerUtils.cpp b/libsolidity/CompilerUtils.cpp
index 583d267a5..e11522029 100644
--- a/libsolidity/CompilerUtils.cpp
+++ b/libsolidity/CompilerUtils.cpp
@@ -189,7 +189,14 @@ void CompilerUtils::encodeToMemory(
 			copyToStackTop(argSize - stackPos + dynPointers + 2, _givenTypes[i]->sizeOnStack());
 			solAssert(!!targetType, "Externalable type expected.");
 			TypePointer type = targetType;
-			if (
+			if (_givenTypes[i]->dataStoredIn(DataLocation::Storage) && targetType->isValueType())
+			{
+				// special case: convert storage reference type to value type - this is only
+				// possible for library calls where we just forward the storage reference
+				solAssert(_encodeAsLibraryTypes, "");
+				solAssert(_givenTypes[i]->sizeOnStack() == 1, "");
+			}
+			else if (
 				_givenTypes[i]->dataStoredIn(DataLocation::Storage) ||
 				_givenTypes[i]->dataStoredIn(DataLocation::CallData) ||
 				_givenTypes[i]->category() == Type::Category::StringLiteral
diff --git a/libsolidity/ExpressionCompiler.cpp b/libsolidity/ExpressionCompiler.cpp
index 49bf25594..a4b636963 100644
--- a/libsolidity/ExpressionCompiler.cpp
+++ b/libsolidity/ExpressionCompiler.cpp
@@ -1179,7 +1179,8 @@ void ExpressionCompiler::appendExternalFunctionCall(
 		argumentTypes,
 		_functionType.parameterTypes(),
 		_functionType.padArguments(),
-		_functionType.takesArbitraryParameters()
+		_functionType.takesArbitraryParameters(),
+		isCallCode
 	);
 
 	// Stack now:
diff --git a/test/libsolidity/SolidityEndToEndTest.cpp b/test/libsolidity/SolidityEndToEndTest.cpp
index c40a027aa..26185b411 100644
--- a/test/libsolidity/SolidityEndToEndTest.cpp
+++ b/test/libsolidity/SolidityEndToEndTest.cpp
@@ -5383,6 +5383,32 @@ BOOST_AUTO_TEST_CASE(internal_types_in_library)
 	BOOST_CHECK(callContractFunction("f()") == encodeArgs(u256(4), u256(17)));
 }
 
+BOOST_AUTO_TEST_CASE(differentiate_storage_and_memory_in_libraries)
+{
+	char const* sourceCode = R"(
+		library Lib {
+			function f(uint[] storage x) returns (uint) { return 1; }
+			function f(uint[] memory x) returns (uint) { return 2; }
+		}
+		contract Test {
+			uint[] data;
+			function f() returns (uint a,)
+			{
+				uint[] memory d = data;
+				Lib.f(d)
+				data["abc"].length = 20;
+				data["abc"][4] = 9;
+				data["abc"][17] = 3;
+				a = Lib.find(data["abc"], 9);
+				b = Lib.find(data["abc"], 3);
+			}
+		}
+	)";
+	compileAndRun(sourceCode, 0, "Lib");
+	compileAndRun(sourceCode, 0, "Test", bytes(), map<string, Address>{{"Lib", m_contractAddress}});
+	BOOST_CHECK(callContractFunction("f()") == encodeArgs(u256(4), u256(17)));
+}
+
 BOOST_AUTO_TEST_CASE(short_strings)
 {
 	// This test verifies that the byte array encoding that combines length and data works