From c8cbb980026413fb88bedc9cbdafd3cd979da215 Mon Sep 17 00:00:00 2001
From: Christian Parpart <christian@parpart.family>
Date: Tue, 3 Mar 2020 12:18:26 +0100
Subject: [PATCH] [Sol2Yul] Fixes appendExternalFunctionCall for
 argumentStrings.size() == 0.

---
 libsolidity/codegen/ir/IRGeneratorForStatements.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libsolidity/codegen/ir/IRGeneratorForStatements.cpp b/libsolidity/codegen/ir/IRGeneratorForStatements.cpp
index 38d16eb69..f35b81f4e 100644
--- a/libsolidity/codegen/ir/IRGeneratorForStatements.cpp
+++ b/libsolidity/codegen/ir/IRGeneratorForStatements.cpp
@@ -47,6 +47,7 @@ using namespace std;
 using namespace solidity;
 using namespace solidity::util;
 using namespace solidity::frontend;
+using namespace std::string_literals;
 
 namespace
 {
@@ -1204,7 +1205,7 @@ void IRGeneratorForStatements::appendExternalFunctionCall(
 		argumentTypes.emplace_back(&type(*arg));
 		argumentStrings.emplace_back(IRVariable(*arg).commaSeparatedList());
 	}
-	string argumentString = ", " + joinHumanReadable(argumentStrings);
+	string argumentString = argumentStrings.empty() ? ""s : (", " + joinHumanReadable(argumentStrings));
 
 	solUnimplementedAssert(funKind != FunctionType::Kind::ECRecover, "");