[gnome-builder] clang: only return result set once

[Christian Hergert <chergert src gnome org>]

commit f7f7e5647970a2f4c4a5e53f8a51d2806e2b89d4
Author: Christian Hergert <chergert redhat com>
Date:   Sun Mar 25 17:17:14 2018 -0700

    clang: only return result set once
    
    We exhaust the information structures after the first call. So no need to
    return anything on follow up calls.

 src/plugins/clang/ide-clang-code-index-entries.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)
---
diff --git a/src/plugins/clang/ide-clang-code-index-entries.c 
b/src/plugins/clang/ide-clang-code-index-entries.c
index 8fcb66f85..9f565816c 100644
--- a/src/plugins/clang/ide-clang-code-index-entries.c
+++ b/src/plugins/clang/ide-clang-code-index-entries.c
@@ -55,6 +55,9 @@ struct _IdeClangCodeIndexEntries
 
   /* Path to the file that has been parsed. */
   gchar *path;
+
+  /* If we've already run once, (so return empty result). */
+  guint has_run : 1;
 };
 
 static void
@@ -376,7 +379,15 @@ ide_clang_code_index_entries_next_entries_async (IdeCodeIndexEntries *entries,
   ide_task_set_source_tag (task, ide_clang_code_index_entries_next_entries_async);
   ide_task_set_priority (task, G_PRIORITY_LOW + 1000);
   ide_task_set_kind (task, IDE_TASK_KIND_INDEXER);
-  ide_task_run_in_thread (task, ide_clang_code_index_entries_worker);
+
+  if (self->has_run)
+    ide_task_return_pointer (task,
+                             g_ptr_array_new_with_free_func ((GDestroyNotify)ide_code_index_entry_free),
+                             (GDestroyNotify)g_ptr_array_unref);
+  else
+    ide_task_run_in_thread (task, ide_clang_code_index_entries_worker);
+
+  self->has_run = TRUE;
 }
 
 static GPtrArray *