[nautilus/antoniof/241-wrong-use-of-g_list_length-to-know-if-a-glist-is-empty] general: Don't iterate GList to check for empty

[António Fernandes <antoniof src gnome org>]

commit 02be3ec3dfca458d21dd19fe634daab72980862f
Author: António Fernandes <antoniof gnome org>
Date:   Wed Feb 7 19:45:59 2018 +0000

    general: Don't iterate GList to check for empty
    
    According to `g_list_length()` API documentaion: "To check whether
    the list is non-empty, it is faster to check list against NULL."
    
    Checking `GList`s against `NULL` is already common in this codebase.
    
    Weed out the few checks of `g_list_length()` against `0` or `< 1`.
    
    Closes https://gitlab.gnome.org/GNOME/nautilus/issues/241

 src/nautilus-progress-persistence-handler.c | 9 ++++-----
 src/nautilus-properties-window.c            | 2 +-
 src/nautilus-window.c                       | 4 ++--
 3 files changed, 7 insertions(+), 8 deletions(-)
---
diff --git a/src/nautilus-progress-persistence-handler.c b/src/nautilus-progress-persistence-handler.c
index cc104fb6a..77ffdcdd8 100644
--- a/src/nautilus-progress-persistence-handler.c
+++ b/src/nautilus-progress-persistence-handler.c
@@ -127,8 +127,7 @@ nautilus_progress_persistence_handler_make_persistent (NautilusProgressPersisten
     GList *windows;
 
     windows = nautilus_application_get_windows (self->app);
-    if (self->active_infos > 0 &&
-        g_list_length (windows) == 0)
+    if (self->active_infos > 0 && windows == NULL)
     {
         progress_persistence_handler_update_notification (self);
     }
@@ -177,12 +176,12 @@ progress_info_finished_cb (NautilusProgressInfo               *info,
     windows = nautilus_application_get_windows (self->app);
     if (self->active_infos > 0)
     {
-        if (g_list_length (windows) == 0)
+        if (windows == NULL)
         {
             progress_persistence_handler_update_notification (self);
         }
     }
-    else if (g_list_length (windows) == 0)
+    else if (windows == NULL)
     {
         progress_persistence_handler_hide_notification (self);
         progress_persistence_handler_show_complete_notification (self);
@@ -200,7 +199,7 @@ handle_new_progress_info (NautilusProgressPersistenceHandler *self,
     self->active_infos++;
     windows = nautilus_application_get_windows (self->app);
 
-    if (g_list_length (windows) == 0)
+    if (windows == NULL)
     {
         progress_persistence_handler_update_notification (self);
     }
diff --git a/src/nautilus-properties-window.c b/src/nautilus-properties-window.c
index 14302204c..3fb9f6a61 100644
--- a/src/nautilus-properties-window.c
+++ b/src/nautilus-properties-window.c
@@ -2303,7 +2303,7 @@ directory_contents_value_field_update (NautilusPropertiesWindow *window)
         }
     }
 
-    deep_count_active = (g_list_length (window->details->deep_count_files) > 0);
+    deep_count_active = (window->details->deep_count_files != NULL);
     /* If we've already displayed the total once, don't do another visible
      * count-up if the deep_count happens to get invalidated.
      * But still display the new total, since it might have changed.
diff --git a/src/nautilus-window.c b/src/nautilus-window.c
index 83f4c23b7..0d689ca15 100644
--- a/src/nautilus-window.c
+++ b/src/nautilus-window.c
@@ -1215,7 +1215,7 @@ places_sidebar_drag_action_requested_cb (GtkPlacesSidebar *sidebar,
     }
     uri = g_file_get_uri (dest_file);
 
-    if (g_list_length (items) < 1)
+    if (items == NULL)
     {
         goto out;
     }
@@ -1848,7 +1848,7 @@ nautilus_window_on_undo_changed (NautilusFileUndoManager *manager,
             /* Don't pop up a notification if user canceled the operation or the focus
              * is not in the this window. This is an easy way to know from which window
              * was the delete operation made */
-            if (g_list_length (files) > 0 && gtk_window_has_toplevel_focus (GTK_WINDOW (window)))
+            if (files != NULL && gtk_window_has_toplevel_focus (GTK_WINDOW (window)))
             {
                 popup_notification = TRUE;
                 label = in_app_notification_undo_deleted_get_label (undo_info);