test(heap): Extend task tracking test with task handle check

Add a test to make sure that the task handles returned in the
task tracking information are valid task handles.

To verify that, feed the task name returned by pcTaskGetName()
using the task handle under test to xTaskGetHandle() and make
sure the task handle returned matches the one under test.

components/heap/test_apps/heap_tests/main/test_task_tracking.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2022-2024 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Unlicense OR CC0-1.0
  */
@@ -49,6 +49,16 @@ static void check_heap_task_info(TaskHandle_t taskHdl)
             // heap_caps_get_per_task_info includes the size of the block owner (4 bytes)
             TEST_ASSERT(heap_info.totals[i].size[0] == ALLOC_BYTES + 4);
         }
+
+        // test that if not 0, the task handle corresponds to an actual task.
+        // this test is to make sure no rubbish is stored as a task handle.
+        if (heap_info.totals[i].task != 0) {
+            // feeding the task name returned by pcTaskGetName() to xTaskGetHandle().
+            // xTaskGetHandle would return the task handler used as parameter in
+            // pcTaskGetName if the task handle is valid. Otherwise, it will return
+            // NULL or just crash if the pointer to the task name is complete nonsense.
+            TEST_ASSERT_EQUAL(heap_info.totals[i].task, xTaskGetHandle(pcTaskGetName(heap_info.totals[i].task)));
+        }
     }
     TEST_ASSERT_TRUE(task_found);
 }