[libshumate] demos: Fix ShumateTestTileSource not implementing fill_tile_finish

[Corentin Noël <corentinnoel src gnome org>]

commit 4804d64d5df46e4bc50da1ed30d2b0114ded9167
Author: Corentin Noël <corentin noel collabora com>
Date:   Thu Jan 13 23:21:33 2022 +0100

    demos: Fix ShumateTestTileSource not implementing fill_tile_finish
    
    Avoid crashing the demo application by simply implementing it.

 demos/shumate-test-tile-source.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)
---
diff --git a/demos/shumate-test-tile-source.c b/demos/shumate-test-tile-source.c
index c9ce238..e364807 100644
--- a/demos/shumate-test-tile-source.c
+++ b/demos/shumate-test-tile-source.c
@@ -110,6 +110,18 @@ shumate_test_tile_source_fill_tile_async (ShumateMapSource *map_source,
   g_task_return_boolean (task, TRUE);
 }
 
+static gboolean
+shumate_test_tile_source_fill_tile_finish (ShumateMapSource *map_source,
+                                           GAsyncResult *result,
+                                           GError **error)
+{
+  ShumateTestTileSource *self = (ShumateTestTileSource *)map_source;
+
+  g_return_val_if_fail (SHUMATE_IS_TEST_TILE_SOURCE (self), FALSE);
+  g_return_val_if_fail (g_task_is_valid (result, self), FALSE);
+
+  return g_task_propagate_boolean (G_TASK (result), error);
+}
 
 static void
 shumate_test_tile_source_class_init (ShumateTestTileSourceClass *klass)
@@ -117,6 +129,7 @@ shumate_test_tile_source_class_init (ShumateTestTileSourceClass *klass)
   ShumateMapSourceClass *map_source_class = SHUMATE_MAP_SOURCE_CLASS (klass);
 
   map_source_class->fill_tile_async = shumate_test_tile_source_fill_tile_async;
+  map_source_class->fill_tile_finish = shumate_test_tile_source_fill_tile_finish;
 }