Doublefree: Fixed FP when exit() is called

lib/checkleakautovar.cpp

@@ -168,6 +168,14 @@ void CheckLeakAutoVar::checkScope(const Token * const startToken,
         if (tok->str() == "(" && tok->previous()->isName()) {
             functionCall(tok->previous(), varInfo, NOALLOC);
             tok = tok->link();
+
+            if (Token::simpleMatch(tok,") ; }")) {
+                bool unknown = false;
+                const bool noreturn = _tokenizer->IsScopeNoReturn(tok->tokAt(2), &unknown);
+                if (noreturn)
+                    varInfo->clear();
+            }
+
             continue;
         }
 

test/testleakautovar.cpp

@@ -57,6 +57,7 @@ private:
         TEST_CASE(doublefree1);
         TEST_CASE(doublefree2);
         TEST_CASE(doublefree3); // #4914
+        TEST_CASE(doublefree4); // #5451 - FP when exit is called
 
         // exit
         TEST_CASE(exit1);
@@ -348,6 +349,17 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void doublefree4() {  // #5451 - exit
+        check("void foo(char *p) {\n"
+              "   if (x) {\n"
+              "       free(p)\n"
+              "       exit(1);\n"
+              "   }\n"
+              "   free(p);\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void exit1() {
         check("void f() {\n"
               "    char *p = malloc(10);\n"