Fix #14209 FN invalidLifetime (struct returned from subfunction, regression) (danmar#8144)

Author: chrchr-github

lib/valueflow.cpp

@@ -2700,7 +2700,8 @@ static void valueFlowLifetimeClassConstructor(Token* tok,
                 if (isDesignatedInitializerArg)
                     ls.argtok = ls.argtok->astOperand2();
                 const Variable &var = *it;
-                if (var.valueType() && var.valueType()->container && var.valueType()->container->stdStringLike && !var.valueType()->container->view)
+                if (ls.argtok->valueType() && ls.argtok->valueType()->pointer &&
+                    var.valueType() && var.valueType()->container && var.valueType()->container->stdStringLike && !var.valueType()->container->view)
                     return; // TODO: check in isLifetimeBorrowed()?
                 if (var.isReference() || var.isRValueReference()) {
                     ls.byRef(tok, tokenlist, errorLogger, settings);

test/testautovariables.cpp

@@ -3957,6 +3957,15 @@ class TestAutoVariables : public TestFixture {
             "[test.cpp:6:30] -> [test.cpp:6:30] -> [test.cpp:6:21] -> [test.cpp:5:21] -> [test.cpp:8:12]: (error) Returning object that points to local variable 'a' that will be invalid when returning. [returnDanglingLifetime]\n",
             errout_str());
 
+        check("struct S { const std::string& r; };\n" // #14209
+              "S f() {\n"
+              "    std::string s;\n"
+              "    return S{ s };\n"
+              "}\n");
+        ASSERT_EQUALS(
+            "[test.cpp:4:15] -> [test.cpp:3:17] -> [test.cpp:4:13]: (error) Returning object that points to local variable 's' that will be invalid when returning. [returnDanglingLifetime]\n",
+            errout_str());
+
         check("struct A { int& x; };\n" // #14247
               "A f() {\n"
               "    int x = 0;\n"