4 files changed, 39 insertions, 25 deletions

diff --git a/libsolidity/analysis/SemVerHandler.cpp b/libsolidity/analysis/SemVerHandler.cpp
index 42186396..29f6d5de 100644
--- a/libsolidity/analysis/SemVerHandler.cpp
+++ b/libsolidity/analysis/SemVerHandler.cpp
@@ -106,18 +106,22 @@ bool SemVerMatchExpression::MatchComponent::matches(SemVerVersion const& _versio
 			}
 		if (cmp == 0 && !_version.prerelease.empty() && didCompare)
 			cmp = -1;
-		if (prefix == Token::Assign)
+
+		switch (prefix)
+		{
+		case Token::Assign:
 			return cmp == 0;
-		else if (prefix == Token::LessThan)
+		case Token::LessThan:
 			return cmp < 0;
-		else if (prefix == Token::LessThanOrEqual)
+		case Token::LessThanOrEqual:
 			return cmp <= 0;
-		else if (prefix == Token::GreaterThan)
+		case Token::GreaterThan:
 			return cmp > 0;
-		else if (prefix == Token::GreaterThanOrEqual)
+		case Token::GreaterThanOrEqual:
 			return cmp >= 0;
-		else
+		default:
 			solAssert(false, "Invalid SemVer expression");
+		}
 		return false;
 	}
 }
@@ -196,21 +200,22 @@ SemVerMatchExpression::MatchComponent SemVerMatchExpressionParser::parseMatchCom
 {
 	SemVerMatchExpression::MatchComponent component;
 	Token::Value token = currentToken();
-	if (
-		token == Token::BitXor ||
-		token == Token::BitNot ||
-		token == Token::LessThan ||
-		token == Token::LessThanOrEqual||
-		token == Token::GreaterThan ||
-		token == Token::GreaterThanOrEqual ||
-		token == Token::Assign
-	)
+
+	switch (token)
 	{
+	case Token::BitXor:
+	case Token::BitNot:
+	case Token::LessThan:
+	case Token::LessThanOrEqual:
+	case Token::GreaterThan:
+	case Token::GreaterThanOrEqual:
+	case Token::Assign:
 		component.prefix = token;
 		nextToken();
-	}
-	else
+		break;
+	default:
 		component.prefix = Token::Assign;
+	}
 
 	component.levelsPresent = 0;
 	while (component.levelsPresent < 3)
diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index 3056561b..c42a0068 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -1778,9 +1778,7 @@ bool TypeChecker::visit(FunctionCall const& _functionCall)
 			}
 			if (resultType->category() == Type::Category::Address)
 			{
-				bool payable = true;
-				if (auto const* contractType = dynamic_cast<ContractType const*>(argType.get()))
-					payable = contractType->isPayable();
+				bool payable = argType->isExplicitlyConvertibleTo(AddressType::addressPayable());
 				resultType = make_shared<AddressType>(payable ? StateMutability::Payable : StateMutability::NonPayable);
 			}
 		}
diff --git a/libsolidity/ast/Types.cpp b/libsolidity/ast/Types.cpp
index 56735698..c97ee657 100644
--- a/libsolidity/ast/Types.cpp
+++ b/libsolidity/ast/Types.cpp
@@ -666,7 +666,7 @@ TypePointer IntegerType::binaryOperatorResult(Token::Value _operator, TypePointe
 			return TypePointer();
 	}
 
-	auto commonType = Type::commonType(shared_from_this(), _other); //might be a integer or fixed point
+	auto commonType = Type::commonType(shared_from_this(), _other); //might be an integer or fixed point
 	if (!commonType)
 		return TypePointer();
 
@@ -2126,8 +2126,11 @@ bool StructType::canBeUsedExternally(bool _inLibrary) const
 		// passed by value and thus the encoding does not differ, but it will disallow
 		// mappings.
 		for (auto const& var: m_struct.members())
+		{
+			solAssert(var->annotation().type, "");
 			if (!var->annotation().type->canBeUsedExternally(false))
 				return false;
+		}
 	}
 	return true;
 }
@@ -2641,8 +2644,8 @@ bool FunctionType::operator==(Type const& _other) const
 
 bool FunctionType::isExplicitlyConvertibleTo(Type const& _convertTo) const
 {
-	if (m_kind == Kind::External && _convertTo.category() == Category::Address)
-			return true;
+	if (m_kind == Kind::External && _convertTo == AddressType::address())
+		return true;
 	return _convertTo.category() == category();
 }
 
diff --git a/libsolidity/interface/StandardCompiler.cpp b/libsolidity/interface/StandardCompiler.cpp
index c1996777..b53c5a5e 100644
--- a/libsolidity/interface/StandardCompiler.cpp
+++ b/libsolidity/interface/StandardCompiler.cpp
@@ -280,6 +280,8 @@ Json::Value StandardCompiler::compileInternal(Json::Value const& _input)
 
 			for (auto const& url: sources[sourceName]["urls"])
 			{
+				if (!url.isString())
+					return formatFatalError("JSONError", "URL must be a string.");
 				ReadCallback::Result result = m_readFile(url.asString());
 				if (result.success)
 				{
@@ -320,7 +322,9 @@ Json::Value StandardCompiler::compileInternal(Json::Value const& _input)
 
 	if (settings.isMember("evmVersion"))
 	{
-		boost::optional<EVMVersion> version = EVMVersion::fromString(settings.get("evmVersion", {}).asString());
+		if (!settings["evmVersion"].isString())
+			return formatFatalError("JSONError", "evmVersion must be a string.");
+		boost::optional<EVMVersion> version = EVMVersion::fromString(settings["evmVersion"].asString());
 		if (!version)
 			return formatFatalError("JSONError", "Invalid EVM version requested.");
 		m_compilerStack.setEVMVersion(*version);
@@ -329,6 +333,8 @@ Json::Value StandardCompiler::compileInternal(Json::Value const& _input)
 	vector<CompilerStack::Remapping> remappings;
 	for (auto const& remapping: settings.get("remappings", Json::Value()))
 	{
+		if (!remapping.isString())
+			return formatFatalError("JSONError", "Remapping entry must be a string.");
 		if (auto r = CompilerStack::parseRemapping(remapping.asString()))
 			remappings.emplace_back(std::move(*r));
 		else
@@ -349,9 +355,11 @@ Json::Value StandardCompiler::compileInternal(Json::Value const& _input)
 	{
 		auto const& jsonSourceName = jsonLibraries[sourceName];
 		if (!jsonSourceName.isObject())
-			return formatFatalError("JSONError", "library entry is not a JSON object.");
+			return formatFatalError("JSONError", "Library entry is not a JSON object.");
 		for (auto const& library: jsonSourceName.getMemberNames())
 		{
+			if (!jsonSourceName[library].isString())
+				return formatFatalError("JSONError", "Library address must be a string.");
 			string address = jsonSourceName[library].asString();
 
 			if (!boost::starts_with(address, "0x"))