comctl32/tests: Test that headers do not free their image list.

dlls/comctl32/tests/header.c

@@ -955,6 +955,7 @@ static void test_hdm_imageMessages(HWND hParent)
 {
     HIMAGELIST hImageList = ImageList_Create (4, 4, 0, 1, 0);
     HIMAGELIST hIml;
+    BOOL wasValid;
     HWND hChild;
 
     flush_sequences(sequences, NUM_MSG_SEQUENCES);
@@ -977,6 +978,10 @@ static void test_hdm_imageMessages(HWND hParent)
     ok_sequence(sequences, HEADER_SEQ_INDEX, imageMessages_seq, "imageMessages sequence testing", FALSE);
 
     DestroyWindow(hChild);
+
+    wasValid = ImageList_Destroy(hImageList);
+todo_wine
+    ok(wasValid, "Header must not free image list at destruction!\n");
 }
 
 static void test_hdm_filterMessages(HWND hParent)