[gnome-photos] Sprinkle some comments about tracker_sparql_cursor_next_finish

[Debarshi Ray <debarshir src gnome org>]

commit 8d48e18ba337896f728b60e02b1738fd2634eafe
Author: Debarshi Ray <debarshir gnome org>
Date:   Tue Nov 29 14:45:06 2016 +0100

    Sprinkle some comments about tracker_sparql_cursor_next_finish

 src/photos-fetch-collections-job.c |    3 +++
 src/photos-fetch-ids-job.c         |    3 +++
 src/photos-single-item-job.c       |    3 +++
 3 files changed, 9 insertions(+), 0 deletions(-)
---
diff --git a/src/photos-fetch-collections-job.c b/src/photos-fetch-collections-job.c
index e6038a3..da23db9 100644
--- a/src/photos-fetch-collections-job.c
+++ b/src/photos-fetch-collections-job.c
@@ -69,6 +69,9 @@ photos_fetch_collections_job_cursor_next (GObject *source_object, GAsyncResult *
   cancellable = g_task_get_cancellable (task);
 
   error = NULL;
+  /* Note that tracker_sparql_cursor_next_finish can return FALSE even
+   * without an error.
+   */
   success = tracker_sparql_cursor_next_finish (cursor, res, &error);
   if (error != NULL)
     {
diff --git a/src/photos-fetch-ids-job.c b/src/photos-fetch-ids-job.c
index 442231c..ff12a38 100644
--- a/src/photos-fetch-ids-job.c
+++ b/src/photos-fetch-ids-job.c
@@ -68,6 +68,9 @@ photos_fetch_ids_job_cursor_next (GObject *source_object, GAsyncResult *res, gpo
   cancellable = g_task_get_cancellable (task);
 
   error = NULL;
+  /* Note that tracker_sparql_cursor_next_finish can return FALSE even
+   * without an error.
+   */
   success = tracker_sparql_cursor_next_finish (cursor, res, &error);
   if (error != NULL)
     {
diff --git a/src/photos-single-item-job.c b/src/photos-single-item-job.c
index 94ccb8b..2ca93e4 100644
--- a/src/photos-single-item-job.c
+++ b/src/photos-single-item-job.c
@@ -67,6 +67,9 @@ photos_single_item_job_cursor_next (GObject *source_object, GAsyncResult *res, g
   gpointer result = NULL;
 
   error = NULL;
+  /* Note that tracker_sparql_cursor_next_finish can return FALSE even
+   * without an error.
+   */
   success = tracker_sparql_cursor_next_finish (cursor, res, &error);
   if (error != NULL)
     {