CPP: Add a test of a template instantiation where the destructor is never called.

Author: geoffw0

cpp/ql/test/query-tests/jsf/4.10 Classes/AV Rule 79/AV Rule 79.expected

@@ -11,6 +11,7 @@
 | ExternalOwners.cpp:49:3:49:20 | ... = ... | Resource a is acquired by class MyScreen but not released anywhere in this class. |
 | ListDelete.cpp:21:3:21:21 | ... = ... | Resource first is acquired by class MyThingColection but not released anywhere in this class. |
 | NoDestructor.cpp:23:3:23:20 | ... = ... | Resource n is acquired by class MyClass5 but not released anywhere in this class. |
+| NoDestructor.cpp:75:3:75:21 | ... = ... | Resource ptr is acquired by class TemplateWithDestructor<int *> but not released anywhere in this class. |
 | PlacementNew.cpp:36:3:36:36 | ... = ... | Resource p1 is acquired by class MyTestForPlacementNew but not released anywhere in this class. |
 | SelfRegistering.cpp:25:3:25:24 | ... = ... | Resource side is acquired by class MyOwner but not released anywhere in this class. |
 | Variants.cpp:25:3:25:13 | ... = ... | Resource f is acquired by class MyClass4 but not released anywhere in this class. |

cpp/ql/test/query-tests/jsf/4.10 Classes/AV Rule 79/NoDestructor.cpp

@@ -66,3 +66,25 @@ class MyClass7 : public MyClass7Base
 		n = new MyNumber(200); // GOOD: deleted in base class
 	}
 };
+
+template<class T>
+class TemplateWithDestructor
+{
+public:
+	TemplateWithDestructor(int len) {
+		ptr = new char[len]; // GOOD [FALSE POSITIVE]
+	}
+
+	~TemplateWithDestructor()
+	{
+		delete [] ptr;
+	}
+
+private:
+	char *ptr;
+};
+
+void test() {
+	TemplateWithDestructor<int *> *t_ptr = new TemplateWithDestructor<int *>(10);
+	//delete t_ptr; --- destructor never used
+}