From a25bc07b77296bb7f6aab4c850bb16d83fc96ced Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Tue, 13 Aug 2024 14:59:46 +0200
Subject: [PATCH] Fix #13011 (False positive: returnByReference should not be
 recommended for non const method marked with &&) (#6689)

---
 lib/checkclass.cpp | 3 +++
 test/testclass.cpp | 7 +++++++
 2 files changed, 10 insertions(+)

diff --git a/lib/checkclass.cpp b/lib/checkclass.cpp
index 86001b691b9..8c525987793 100644
--- a/lib/checkclass.cpp
+++ b/lib/checkclass.cpp
@@ -3345,6 +3345,9 @@ void CheckClass::checkReturnByReference()
             if (const Library::Container* container = mSettings->library.detectContainer(func.retDef))
                 if (container->view)
                     continue;
+            if (!func.isConst() && func.hasRvalRefQualifier())
+                // this method could be used by temporary objects, return by value can be dangerous
+                continue;
             if (const Variable* var = getSingleReturnVar(func.functionScope)) {
                 if (!var->valueType())
                     continue;
diff --git a/test/testclass.cpp b/test/testclass.cpp
index f6490bf76b7..f440381c317 100644
--- a/test/testclass.cpp
+++ b/test/testclass.cpp
@@ -9045,6 +9045,13 @@ class TestClass : public TestFixture {
                                "};\n"
                                "U<std::string> u;\n");
         ASSERT_EQUALS("", errout_str());
+
+        checkReturnByReference("struct S {\n" // #13011
+                               "    std::string s;\n"
+                               "    const std::string& foo() const & { return s; }\n"
+                               "    std::string foo() && { return s; }\n" // <- used for temporary objects
+                               "};\n");
+        ASSERT_EQUALS("", errout_str());
     }
 };