Merge pull request #2635 from ethereum/fixCrashOnAssignmentToNonLValue

Fix crash on assignment to non-LValue

3 files changed, 18 insertions, 1 deletions

diff --git a/Changelog.md b/Changelog.md
index ebd74288..18fd00ea 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -12,6 +12,7 @@ Features:
  * Type checker: Warn when existing symbols, including builtins, are overwritten.
 
 Bugfixes:
+ * Type Checker: Fix crash for some assignment to non-lvalue.
  * Type Checker: Fix invalid "specify storage keyword" warning for reference members of structs.
  * Type Checker: Mark modifiers as internal.
  * Type Checker: Re-allow multiple mentions of the same modifier per function.
diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index 0d04c26d..1ee827d4 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -1122,7 +1122,9 @@ bool TypeChecker::visit(Assignment const& _assignment)
 		_assignment.annotation().type = make_shared<TupleType>();
 		expectType(_assignment.rightHandSide(), *tupleType);
 
-		checkDoubleStorageAssignment(_assignment);
+		// expectType does not cause fatal errors, so we have to check again here.
+		if (dynamic_cast<TupleType const*>(type(_assignment.rightHandSide()).get()))
+			checkDoubleStorageAssignment(_assignment);
 	}
 	else if (t->category() == Type::Category::Mapping)
 	{
diff --git a/test/libsolidity/SolidityNameAndTypeResolution.cpp b/test/libsolidity/SolidityNameAndTypeResolution.cpp
index accf86c6..cd922cc8 100644
--- a/test/libsolidity/SolidityNameAndTypeResolution.cpp
+++ b/test/libsolidity/SolidityNameAndTypeResolution.cpp
@@ -6437,6 +6437,20 @@ BOOST_AUTO_TEST_CASE(using_this_in_constructor)
 	CHECK_WARNING(text, "\"this\" used in constructor");
 }
 
+BOOST_AUTO_TEST_CASE(do_not_crash_on_not_lalue)
+{
+	// This checks for a bug that caused a crash because of continued analysis.
+	char const* text = R"(
+		contract C {
+			mapping (uint => uint) m;
+			function f() {
+				m(1) = 2;
+			}
+		}
+	)";
+	CHECK_ERROR_ALLOW_MULTI(text, TypeError, "is not callable");
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 }