Fix #13373 FP returnReference for reference member (#7066)

Author: chrchr-github

lib/valueflow.cpp

@@ -1585,7 +1585,8 @@ static std::vector<ValueFlow::LifetimeToken> getLifetimeTokens(const Token* tok,
             if (vartok->str() == "[" || vartok->isUnaryOp("*"))
                 vartok = vartok->astOperand1();
             else if (vartok->str() == ".") {
-                if (vartok->originalName().empty() || !Token::simpleMatch(vartok->astOperand1(), "."))
+                if (!Token::simpleMatch(vartok->astOperand1(), ".") &&
+                    !(vartok->astOperand2() && vartok->astOperand2()->valueType() && vartok->astOperand2()->valueType()->reference != Reference::None))
                     vartok = vartok->astOperand1();
                 else
                     break;

test/testautovariables.cpp

@@ -119,6 +119,7 @@ class TestAutoVariables : public TestFixture {
         TEST_CASE(returnReference25); // #10983
         TEST_CASE(returnReference26);
         TEST_CASE(returnReference27);
+        TEST_CASE(returnReference28);
         TEST_CASE(returnReferenceFunction);
         TEST_CASE(returnReferenceContainer);
         TEST_CASE(returnReferenceLiteral);
@@ -1672,6 +1673,17 @@ class TestAutoVariables : public TestFixture {
         ASSERT_EQUALS("", errout_str());
     }
 
+    void returnReference28()
+    {
+        check("struct S {\n" // #13373
+              "    int& r;\n"
+              "};\n"
+              "int& f(S s) {\n"
+              "    return s.r;\n"
+              "}\n");
+        ASSERT_EQUALS("", errout_str());
+    }
+
     void returnReferenceFunction() {
         check("int& f(int& a) {\n"
               "    return a;\n"