[gnome-builder] xml-pack: clear struct fields when freeing

[Christian Hergert <chergert src gnome org>]

commit 994aca31819a6e65f80c63c510f450d836ad18d3
Author: Christian Hergert <chergert redhat com>
Date:   Fri Jan 12 17:42:45 2018 -0800

    xml-pack: clear struct fields when freeing

 src/plugins/xml-pack/ide-xml-tree-builder.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/src/plugins/xml-pack/ide-xml-tree-builder.c b/src/plugins/xml-pack/ide-xml-tree-builder.c
index e80c264a6..168d871ec 100644
--- a/src/plugins/xml-pack/ide-xml-tree-builder.c
+++ b/src/plugins/xml-pack/ide-xml-tree-builder.c
@@ -128,8 +128,9 @@ typedef struct _FetchSchemasState
 static void
 fetch_schema_state_free (FetchSchemasState *state)
 {
-  g_object_unref (state->self);
-  g_ptr_array_unref (state->schemas);
+  g_clear_object (&state->self);
+  g_clear_pointer (&state->schemas, g_ptr_array_unref);
+  self->task = NULL;
 
   g_slice_free (FetchSchemasState, state);
 }