fix: disambiguate library functions vs native properties in member access

libsolidity/analysis/TypeChecker.cpp

@@ -3175,13 +3175,19 @@ bool TypeChecker::visit(MemberAccess const& _memberAccess)
 	size_t const initialMemberCount = possibleMembers.size();
 	if (initialMemberCount > 1 && arguments)
 	{
-		// do overload resolution
+		// Do overload resolution, and filter out non-functions when called with parentheses.
+		// This allows library functions like OpenZeppelin's Address.isContract() to work
+		// alongside Tron's native address.isContract property.
+		// Mirrors the identifier resolution pattern at lines 3693-3745 where
+		// VariableDeclarations are preferred without parentheses.
 		for (auto it = possibleMembers.begin(); it != possibleMembers.end();)
 			if (
 				it->type->category() == Type::Category::Function &&
 				!dynamic_cast<FunctionType const&>(*it->type).canTakeArguments(*arguments, exprType)
 			)
 				it = possibleMembers.erase(it);
+			else if (it->type->category() != Type::Category::Function)
+				it = possibleMembers.erase(it);
 			else
 				++it;
 	}

test/libsolidity/syntaxTests/memberLookup/library_function_vs_native_property_with_parens.sol

@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.8.0;
+
+// Test that library function is preferred over native property when called with parentheses.
+// This allows OpenZeppelin's Address.isContract() to work alongside Tron's native address.isContract property.
+library Address {
+    function isContract(address account) internal view returns (bool) {
+        return account.code.length > 0;
+    }
+}
+
+contract C {
+    using Address for address;
+
+    function check(address a) public view returns (bool) {
+        // With parentheses - should use library function
+        return a.isContract();
+    }
+}
+// ----

test/libsolidity/syntaxTests/memberLookup/library_function_vs_native_property_without_parens.sol

@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.8.0;
+
+// Test that accessing a member without parentheses when both a native property
+// and a library function exist with the same name results in an ambiguity error.
+// Users should use the native property syntax directly without "using for" to avoid this.
+library Address {
+    function isContract(address account) internal view returns (bool) {
+        return account.code.length > 0;
+    }
+}
+
+contract C {
+    using Address for address;
+
+    function check(address a) public view returns (bool) {
+        // Without parentheses - ambiguous between native property and library function
+        return a.isContract;
+    }
+}
+// ----
+// TypeError 6675: (519-531): Member "isContract" not unique after argument-dependent lookup in address.

test/libsolidity/syntaxTests/memberLookup/native_isContract_property.sol

@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.8.0;
+
+// Test Tron's native address.isContract property works without library.
+contract C {
+    function check(address a) public view returns (bool) {
+        return a.isContract;
+    }
+}
+// ----