Fix #11561 FN nullPointer with unnamed parameter (#4805)

Author: chrchr-github

lib/valueflow.cpp

@@ -7529,7 +7529,7 @@ static void valueFlowFunctionReturn(TokenList *tokenlist, ErrorLogger *errorLogg
         ProgramMemory programMemory;
         for (std::size_t i = 0; i < parvalues.size(); ++i) {
             const Variable * const arg = function->getArgumentVar(i);
-            if (!arg || !Token::Match(arg->typeStartToken(), "%type% %name% ,|)")) {
+            if (!arg) {
                 if (tokenlist->getSettings()->debugwarnings)
                     bailout(tokenlist, errorLogger, tok, "function return; unhandled argument type");
                 programMemory.clear();

test/testnullpointer.cpp

@@ -3707,6 +3707,11 @@ class TestNullPointer : public TestFixture {
         ASSERT_EQUALS("[test.cpp:3]: (error) Null pointer dereference: p\n"
                       "[test.cpp:4]: (error) Null pointer dereference\n",
                       errout.str());
+
+        check("const char* g(long) { return nullptr; }\n" // #11561
+              "void f() { std::string s = g(0L); }\n");
+        ASSERT_EQUALS("[test.cpp:2]: (error) Null pointer dereference: g(0L)\n",
+                      errout.str());
     }
 
     void nullpointerStdStream() {