Merge pull request #4465 from ethereum/tupleAssignment

Disallow tuple assignment with mismatching number of components.

2 files changed, 5 insertions, 35 deletions

diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index ed7f05f7..20e423e6 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -1337,7 +1337,6 @@ bool TypeChecker::visit(Conditional const& _conditional)
 
 bool TypeChecker::visit(Assignment const& _assignment)
 {
-	bool const v050 = m_scope->sourceUnit().annotation().experimentalFeatures.count(ExperimentalFeature::V050);
 	requireLValue(_assignment.leftHandSide());
 	TypePointer t = type(_assignment.leftHandSide());
 	_assignment.annotation().type = t;
@@ -1354,25 +1353,8 @@ bool TypeChecker::visit(Assignment const& _assignment)
 		expectType(_assignment.rightHandSide(), *tupleType);
 
 		// expectType does not cause fatal errors, so we have to check again here.
-		if (TupleType const* rhsType = dynamic_cast<TupleType const*>(type(_assignment.rightHandSide()).get()))
-		{
+		if (dynamic_cast<TupleType const*>(type(_assignment.rightHandSide()).get()))
 			checkDoubleStorageAssignment(_assignment);
-			// @todo For 0.5.0, this code shoud move to TupleType::isImplicitlyConvertibleTo,
-			// but we cannot do it right now.
-			if (rhsType->components().size() != tupleType->components().size())
-			{
-				string message =
-					"Different number of components on the left hand side (" +
-					toString(tupleType->components().size()) +
-					") than on the right hand side (" +
-					toString(rhsType->components().size()) +
-					").";
-				if (v050)
-					m_errorReporter.typeError(_assignment.location(), message);
-				else
-					m_errorReporter.warning(_assignment.location(), message);
-			}
-		}
 	}
 	else if (t->category() == Type::Category::Mapping)
 	{
diff --git a/libsolidity/ast/Types.cpp b/libsolidity/ast/Types.cpp
index 1c4eb76e..23614e58 100644
--- a/libsolidity/ast/Types.cpp
+++ b/libsolidity/ast/Types.cpp
@@ -2238,25 +2238,13 @@ bool TupleType::isImplicitlyConvertibleTo(Type const& _other) const
 		TypePointers const& targets = tupleType->components();
 		if (targets.empty())
 			return components().empty();
-		if (components().size() != targets.size() && !targets.front() && !targets.back())
-			return false; // (,a,) = (1,2,3,4) - unable to position `a` in the tuple.
-		size_t minNumValues = targets.size();
-		if (!targets.back() || !targets.front())
-			--minNumValues; // wildcards can also match 0 components
-		if (components().size() < minNumValues)
+		if (components().size() != targets.size())
 			return false;
-		if (components().size() > targets.size() && targets.front() && targets.back())
-			return false; // larger source and no wildcard
-		bool fillRight = !targets.back() || targets.front();
-		for (size_t i = 0; i < min(targets.size(), components().size()); ++i)
-		{
-			auto const& s = components()[fillRight ? i : components().size() - i - 1];
-			auto const& t = targets[fillRight ? i : targets.size() - i - 1];
-			if (!s && t)
+		for (size_t i = 0; i < targets.size(); ++i)
+			if (!components()[i] && targets[i])
 				return false;
-			else if (s && t && !s->isImplicitlyConvertibleTo(*t))
+			else if (components()[i] && targets[i] && !components()[i]->isImplicitlyConvertibleTo(*targets[i]))
 				return false;
-		}
 		return true;
 	}
 	else