Added checks for observer_from_this after release/reset

Author: cschreib

tests/runtime_tests.cpp

@@ -3055,6 +3055,57 @@ TEST_CASE("observer from this after move assignment sealed", "[observer_from_thi
     REQUIRE(mem_track.double_del() == 0u);
 }
 
+TEST_CASE("observer from this after release", "[observer_from_this]") {
+    memory_tracker mem_track;
+
+    {
+        test_ptr_from_this ptr1{new test_object_observer_from_this};
+        test_object_observer_from_this* ptr2 = ptr1.release();
+        const test_object_observer_from_this* cptr2 = ptr2;
+
+        test_optr_from_this optr_from_this = ptr2->observer_from_this();
+        test_optr_from_this_const optr_from_this_const = cptr2->observer_from_this();
+
+        REQUIRE(instances == 1);
+        REQUIRE(optr_from_this.expired() == true);
+        REQUIRE(optr_from_this_const.expired() == true);
+        REQUIRE(optr_from_this.get() == nullptr);
+        REQUIRE(optr_from_this_const.get() == nullptr);
+
+        delete ptr2;
+    }
+
+    REQUIRE(instances == 0);
+    REQUIRE(mem_track.leaks() == 0u);
+    REQUIRE(mem_track.double_del() == 0u);
+}
+
+TEST_CASE("observer from this after release and reset", "[observer_from_this]") {
+    memory_tracker mem_track;
+
+    {
+        test_ptr_from_this ptr1{new test_object_observer_from_this};
+        test_object_observer_from_this* ptr2 = ptr1.release();
+        const test_object_observer_from_this* cptr2 = ptr2;
+
+        test_ptr_from_this ptr3;
+        ptr3.reset(ptr2);
+
+        test_optr_from_this optr_from_this = ptr2->observer_from_this();
+        test_optr_from_this_const optr_from_this_const = cptr2->observer_from_this();
+
+        REQUIRE(instances == 1);
+        REQUIRE(optr_from_this.expired() == false);
+        REQUIRE(optr_from_this_const.expired() == false);
+        REQUIRE(optr_from_this.get() == ptr2);
+        REQUIRE(optr_from_this_const.get() == ptr2);
+    }
+
+    REQUIRE(instances == 0);
+    REQUIRE(mem_track.leaks() == 0u);
+    REQUIRE(mem_track.double_del() == 0u);
+}
+
 TEST_CASE("observer from this stack", "[observer_from_this]") {
     memory_tracker mem_track;