shell32/tests: Simple test for KF_FLAG_DEFAULT_PATH.

dlls/shell32/tests/shellpath.c

@@ -860,6 +860,12 @@ if (0) { /* crashes */
     ok(path == NULL, "got %p\n", path);
 
     path = NULL;
+    hr = pSHGetKnownFolderPath(&FOLDERID_Desktop, KF_FLAG_DEFAULT_PATH, NULL, &path);
+    ok(hr == S_OK, "expected S_OK, got 0x%08x\n", hr);
+    ok(path != NULL, "expected path != NULL\n");
+    CoTaskMemFree(path);
+
+    path = NULL;
     hr = pSHGetKnownFolderPath(&FOLDERID_Desktop, 0, NULL, &path);
     ok(hr == S_OK, "expected S_OK, got 0x%08x\n", hr);
     ok(path != NULL, "expected path != NULL\n");