diff --git a/solidityCompiler.cpp b/solidityCompiler.cpp
index 004740b5e..eae8f3142 100644
--- a/solidityCompiler.cpp
+++ b/solidityCompiler.cpp
@@ -87,7 +87,7 @@ BOOST_AUTO_TEST_CASE(smoke_test)
 							 "}\n";
 	bytes code = compileContract(sourceCode);
 
-	unsigned boilerplateSize = 42;
+	unsigned boilerplateSize = 40;
 	bytes expectation({byte(Instruction::JUMPDEST),
 					   byte(Instruction::PUSH1), 0x0, // initialize local variable x
 					   byte(Instruction::PUSH1), 0x2,
@@ -107,8 +107,8 @@ BOOST_AUTO_TEST_CASE(different_argument_numbers)
 							 "}\n";
 	bytes code = compileContract(sourceCode);
 
-	unsigned shift = 70;
-	unsigned boilerplateSize = 83;
+	unsigned shift = 68;
+	unsigned boilerplateSize = 81;
 	bytes expectation({byte(Instruction::JUMPDEST),
 					   byte(Instruction::PUSH1), 0x0, // initialize return variable d
 					   byte(Instruction::DUP3),
@@ -158,8 +158,8 @@ BOOST_AUTO_TEST_CASE(ifStatement)
 							 "}\n";
 	bytes code = compileContract(sourceCode);
 
-	unsigned shift = 29;
-	unsigned boilerplateSize = 42;
+	unsigned shift = 27;
+	unsigned boilerplateSize = 40;
 	bytes expectation({byte(Instruction::JUMPDEST),
 					   byte(Instruction::PUSH1), 0x0,
 					   byte(Instruction::DUP1),
@@ -200,8 +200,8 @@ BOOST_AUTO_TEST_CASE(loops)
 							 "}\n";
 	bytes code = compileContract(sourceCode);
 
-	unsigned shift = 29;
-	unsigned boilerplateSize = 42;
+	unsigned shift = 27;
+	unsigned boilerplateSize = 40;
 	bytes expectation({byte(Instruction::JUMPDEST),
 					   byte(Instruction::JUMPDEST),
 					   byte(Instruction::PUSH1), 0x1,
diff --git a/solidityEndToEndTest.cpp b/solidityEndToEndTest.cpp
index 3c77492a5..af8b58baa 100644
--- a/solidityEndToEndTest.cpp
+++ b/solidityEndToEndTest.cpp
@@ -363,6 +363,48 @@ BOOST_AUTO_TEST_CASE(small_signed_types)
 	testSolidityAgainstCpp(0, small_signed_types_cpp);
 }
 
+BOOST_AUTO_TEST_CASE(strings)
+{
+	char const* sourceCode = "contract test {\n"
+							 "  function fixed() returns(string32 ret) {\n"
+							 "    return \"abc\\x00\\xff__\";\n"
+							 "  }\n"
+							 "  function pipeThrough(string2 small, bool one) returns(string16 large, bool oneRet) {\n"
+							 "    oneRet = one;\n"
+							 "    large = small;\n"
+							 "  }\n"
+							 "}\n";
+	compileAndRun(sourceCode);
+	bytes expectation(32, 0);
+	expectation[0] = byte('a');
+	expectation[1] = byte('b');
+	expectation[2] = byte('c');
+	expectation[3] = byte(0);
+	expectation[4] = byte(0xff);
+	expectation[5] = byte('_');
+	expectation[6] = byte('_');
+	BOOST_CHECK(callContractFunction(0, bytes()) == expectation);
+	expectation = bytes(17, 0);
+	expectation[0] = 0;
+	expectation[1] = 2;
+	expectation[16] = 1;
+	BOOST_CHECK(callContractFunction(1, bytes({0x00, 0x02, 0x01})) == expectation);
+}
+
+BOOST_AUTO_TEST_CASE(empty_string_on_stack)
+{
+	char const* sourceCode = "contract test {\n"
+							 "  function run(string0 empty, uint8 inp) returns(uint16 a, string0 b, string4 c) {\n"
+							 "    var x = \"abc\";\n"
+							 "    var y = \"\";\n"
+							 "    var z = inp;\n"
+							 "    a = z; b = y; c = x;"
+							 "  }\n"
+							 "}\n";
+	compileAndRun(sourceCode);
+	BOOST_CHECK(callContractFunction(0, bytes({0x02})) == bytes({0x00, 0x02, 'a', 'b', 'c', 0x00}));
+}
+
 BOOST_AUTO_TEST_CASE(state_smoke_test)
 {
 	char const* sourceCode = "contract test {\n"
@@ -941,6 +983,34 @@ BOOST_AUTO_TEST_CASE(inter_contract_calls_with_local_vars)
 	BOOST_REQUIRE(callContractFunction(0, a, b) == toBigEndian(a * b + 9));
 }
 
+BOOST_AUTO_TEST_CASE(strings_in_calls)
+{
+	char const* sourceCode = R"(
+		contract Helper {
+			function invoke(string3 x, bool stop) returns (string4 ret) {
+				return x;
+			}
+		}
+		contract Main {
+			Helper h;
+			function callHelper(string2 x, bool stop) returns (string5 ret) {
+				return h.invoke(x, stop);
+			}
+			function getHelper() returns (address addr) {
+				return address(h);
+			}
+			function setHelper(address addr) {
+				h = Helper(addr);
+			}
+		})";
+	compileAndRun(sourceCode, 0, "Helper");
+	u160 const helperAddress = m_contractAddress;
+	compileAndRun(sourceCode, 0, "Main");
+	BOOST_REQUIRE(callContractFunction(2, helperAddress) == bytes());
+	BOOST_REQUIRE(callContractFunction(1, helperAddress) == toBigEndian(helperAddress));
+	BOOST_CHECK(callContractFunction(0, bytes({0, 'a', 1})) == bytes({0, 'a', 0, 0, 0}));
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 }
diff --git a/solidityNameAndTypeResolution.cpp b/solidityNameAndTypeResolution.cpp
index 783972296..03eaebb3a 100644
--- a/solidityNameAndTypeResolution.cpp
+++ b/solidityNameAndTypeResolution.cpp
@@ -226,6 +226,14 @@ BOOST_AUTO_TEST_CASE(type_inference_explicit_conversion)
 	BOOST_CHECK_NO_THROW(parseTextAndResolveNames(text));
 }
 
+BOOST_AUTO_TEST_CASE(large_string_literal)
+{
+	char const* text = "contract test {\n"
+					   "  function f() { var x = \"123456789012345678901234567890123\"; }"
+					   "}\n";
+	BOOST_CHECK_THROW(parseTextAndResolveNames(text), TypeError);
+}
+
 BOOST_AUTO_TEST_CASE(balance)
 {
 	char const* text = "contract test {\n"
diff --git a/solidityOptimizerTest.cpp b/solidityOptimizerTest.cpp
index b689fe54e..388e0579c 100644
--- a/solidityOptimizerTest.cpp
+++ b/solidityOptimizerTest.cpp
@@ -48,7 +48,7 @@ public:
 		m_optimize = true;
 		bytes optimizedBytecode = compileAndRun(_sourceCode, _value, _contractName);
 		int sizeDiff = nonOptimizedBytecode.size() - optimizedBytecode.size();
-		BOOST_CHECK_MESSAGE(sizeDiff >= (int)_expectedSizeDecrease, "Bytecode did only shrink by "
+		BOOST_CHECK_MESSAGE(sizeDiff == int(_expectedSizeDecrease), "Bytecode did only shrink by "
 							+ boost::lexical_cast<string>(sizeDiff) + " bytes, expected: "
 							+ boost::lexical_cast<string>(_expectedSizeDecrease));
 		m_optimizedContract = m_contractAddress;
@@ -106,7 +106,7 @@ BOOST_AUTO_TEST_CASE(invariants)
 				return (((a + (1 - 1)) ^ 0) | 0) & (uint(0) - 1);
 			}
 		})";
-	compileBothVersions(19, sourceCode);
+	compileBothVersions(28, sourceCode);
 	compareVersions(0, u256(0x12334664));
 }
 
@@ -124,6 +124,21 @@ BOOST_AUTO_TEST_CASE(unused_expressions)
 	compareVersions(0);
 }
 
+BOOST_AUTO_TEST_CASE(constant_folding_both_sides)
+{
+	// if constants involving the same associative and commutative operator are applied from both
+	// sides, the operator should be applied only once, because the expression compiler
+	// (even in non-optimized mode) pushes literals as late as possible
+	char const* sourceCode = R"(
+		contract test {
+			function f(uint x) returns (uint y) {
+				return 98 ^ (7 * ((1 | (x | 1000)) * 40) ^ 102);
+			}
+		})";
+	compileBothVersions(31, sourceCode);
+	compareVersions(0);
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 }