Merge pull request #1599 from ethereum/fixErrorTagLLL

Fix error tag usage in lll.

libevmasm/Assembly.cpp

@@ -40,7 +40,7 @@ void Assembly::append(Assembly const& _a)
 	auto newDeposit = m_deposit + _a.deposit();
 	for (AssemblyItem i: _a.m_items)
 	{
-		if (i.type() == Tag || i.type() == PushTag)
+		if (i.type() == Tag || (i.type() == PushTag && i != errorTag()))
 			i.setData(i.data() + m_usedTags);
 		else if (i.type() == PushSub || i.type() == PushSubSize)
 			i.setData(i.data() + m_subs.size());

test/liblll/EndToEndTest.cpp

@@ -50,6 +50,13 @@ BOOST_AUTO_TEST_CASE(bare_panic)
 	BOOST_REQUIRE(m_output.empty());
 }
 
+BOOST_AUTO_TEST_CASE(panic)
+{
+	char const* sourceCode = "{ (panic) }";
+	compileAndRunWithoutCheck(sourceCode);
+	BOOST_REQUIRE(m_output.empty());
+}
+
 BOOST_AUTO_TEST_CASE(exp_operator_const)
 {
 	char const* sourceCode = R"(