Merge pull request #2518 from ethereum/fixInternalVariableAlreadyPresent

Fix internal variable already present error.

3 files changed, 33 insertions, 0 deletions

diff --git a/Changelog.md b/Changelog.md
index 7c0c86a5..b4415978 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,5 +1,8 @@
 ### 0.4.13 (unreleased)
 
+Bugfixes:
+ * Code Generator: Correctly unregister modifier variables.
+
 ### 0.4.12 (2017-07-03)
 
 Features:
diff --git a/libsolidity/codegen/ContractCompiler.cpp b/libsolidity/codegen/ContractCompiler.cpp
index c358a519..cad388df 100644
--- a/libsolidity/codegen/ContractCompiler.cpp
+++ b/libsolidity/codegen/ContractCompiler.cpp
@@ -928,7 +928,10 @@ void ContractCompiler::appendModifierOrFunctionCode()
 				);
 			}
 			for (VariableDeclaration const* localVariable: modifier.localVariables())
+			{
+				addedVariables.push_back(localVariable);
 				appendStackVariableInitialisation(*localVariable);
+			}
 
 			stackSurplus =
 				CompilerUtils::sizeOnStack(modifier.parameters()) +
diff --git a/test/libsolidity/SolidityEndToEndTest.cpp b/test/libsolidity/SolidityEndToEndTest.cpp
index a6c01283..c9771fbd 100644
--- a/test/libsolidity/SolidityEndToEndTest.cpp
+++ b/test/libsolidity/SolidityEndToEndTest.cpp
@@ -9696,6 +9696,33 @@ BOOST_AUTO_TEST_CASE(keccak256_assembly)
 	BOOST_CHECK(callContractFunction("i()") == fromHex("0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470"));
 }
 
+BOOST_AUTO_TEST_CASE(multi_modifiers)
+{
+	// This triggered a bug in some version because the variable in the modifier was not
+	// unregistered correctly.
+	char const* sourceCode = R"(
+		contract C {
+			uint public x;
+			modifier m1 {
+				address a1 = msg.sender;
+				x++;
+				_;
+			}
+			function f1() m1() {
+				x += 7;
+			}
+			function f2() m1() {
+				x += 3;
+			}
+		}
+	)";
+	compileAndRun(sourceCode, 0, "C");
+	BOOST_CHECK(callContractFunction("f1()") == bytes());
+	BOOST_CHECK(callContractFunction("x()") == encodeArgs(u256(8)));
+	BOOST_CHECK(callContractFunction("f2()") == bytes());
+	BOOST_CHECK(callContractFunction("x()") == encodeArgs(u256(12)));
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 }