From 98e5923e3aa5d4606de0ddc71916993478c5f9ae Mon Sep 17 00:00:00 2001
From: chriseth <chris@ethereum.org>
Date: Mon, 22 Jun 2020 18:10:18 +0200
Subject: [PATCH] Do now disallow assigning to external parameters.

---
 Changelog.md                                               | 1 +
 libsolidity/ast/AST.cpp                                    | 7 +------
 .../syntaxTests/lvalues/external_reference_argument.sol    | 1 -
 .../libsolidity/syntaxTests/structs/memory_to_calldata.sol | 2 --
 4 files changed, 2 insertions(+), 9 deletions(-)

diff --git a/Changelog.md b/Changelog.md
index 843d47ba5..91a7fc43f 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -11,6 +11,7 @@ Compiler Features:
 Bugfixes:
  * NatSpec: Do not consider ``////`` and ``/***`` as NatSpec comments.
  * Type Checker: Fix internal error related to ``using for`` applied to non-libraries.
+ * Type Checker: Do not disallow assigning to calldata variables.
  * Yul: Fix source location of variable multi-assignment.
 
 
diff --git a/libsolidity/ast/AST.cpp b/libsolidity/ast/AST.cpp
index 3492bfc45..f3f79f451 100644
--- a/libsolidity/ast/AST.cpp
+++ b/libsolidity/ast/AST.cpp
@@ -492,12 +492,7 @@ DeclarationAnnotation& Declaration::annotation() const
 bool VariableDeclaration::isLValue() const
 {
 	// Constant declared variables are Read-Only
-	if (isConstant())
-		return false;
-	// External function arguments of reference type are Read-Only
-	if (isExternalCallableParameter() && dynamic_cast<ReferenceType const*>(type()))
-		return false;
-	return true;
+	return !isConstant();
 }
 
 bool VariableDeclaration::isLocalVariable() const
diff --git a/test/libsolidity/syntaxTests/lvalues/external_reference_argument.sol b/test/libsolidity/syntaxTests/lvalues/external_reference_argument.sol
index ed638781c..67378653b 100644
--- a/test/libsolidity/syntaxTests/lvalues/external_reference_argument.sol
+++ b/test/libsolidity/syntaxTests/lvalues/external_reference_argument.sol
@@ -4,4 +4,3 @@ contract C {
     }
 }
 // ----
-// TypeError 7128: (96-97): External function arguments of reference type are read-only.
diff --git a/test/libsolidity/syntaxTests/structs/memory_to_calldata.sol b/test/libsolidity/syntaxTests/structs/memory_to_calldata.sol
index d6b2aed6a..19747e9a5 100644
--- a/test/libsolidity/syntaxTests/structs/memory_to_calldata.sol
+++ b/test/libsolidity/syntaxTests/structs/memory_to_calldata.sol
@@ -5,7 +5,5 @@ contract Test {
     function g(S calldata s) external { S memory m; s = m; }
 }
 // ----
-// TypeError 7128: (114-115): External function arguments of reference type are read-only.
 // TypeError 7407: (118-122): Type struct Test.S memory is not implicitly convertible to expected type struct Test.S calldata.
-// TypeError 7128: (178-179): External function arguments of reference type are read-only.
 // TypeError 7407: (182-183): Type struct Test.S memory is not implicitly convertible to expected type struct Test.S calldata.