Fix #8174 Regression: false negative autovarInvalidDeallocation since 1.79 (#5045)

Author: chrchr-github

lib/checkautovariables.cpp

@@ -277,9 +277,10 @@ void CheckAutoVariables::autoVariables()
                     errorInvalidDeallocation(tok, nullptr);
                 else if (tok->variable() && tok->variable()->isPointer()) {
                     for (const ValueFlow::Value &v : tok->values()) {
-                        if (!(v.isTokValue()))
+                        if (v.isImpossible())
                             continue;
-                        if (isArrayVar(v.tokvalue) || ((v.tokvalue->tokType() == Token::eString) && !v.isImpossible())) {
+                        if ((v.isTokValue() && (isArrayVar(v.tokvalue) || ((v.tokvalue->tokType() == Token::eString)))) ||
+                            (v.isLocalLifetimeValue() && v.lifetimeKind == ValueFlow::Value::LifetimeKind::Address)) {
                             errorInvalidDeallocation(tok, &v);
                             break;
                         }

test/testautovariables.cpp

@@ -793,6 +793,23 @@ class TestAutoVariables : public TestFixture {
               "};\n"
               "Array arr;\n");
         ASSERT_EQUALS("", errout.str());
+
+        // #8174
+        check("struct S {};\n"
+              "void f() {\n"
+              "    S s;\n"
+              "    S* p = &s;\n"
+              "    free(p);\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:5]: (error) Deallocation of an auto-variable (s) results in undefined behaviour.\n", errout.str());
+
+        check("void f(bool b, int* q) {\n"
+              "    int i;\n"
+              "    int* p = b ? &i : q;\n"
+              "    if (!b)\n"
+              "        free(p);\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void testinvaliddealloc_input() {