[gnome-screenshot] Use g_autofree/g_autoptr to simplify code

[Cosimo Cecchi <cosimoc src gnome org>]

commit 2a6c090b27c046e48e193939a826bb5a6e889c0f
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Wed Jul 24 13:19:53 2019 +0200

    Use g_autofree/g_autoptr to simplify code

 src/gnome-screenshot.c              |   8 +-
 src/screenshot-application.c        | 101 +++++++-----------------
 src/screenshot-application.h        |   2 +-
 src/screenshot-area-selection.c     |  17 +---
 src/screenshot-dialog.c             |  36 +++------
 src/screenshot-filename-builder.c   | 153 +++++++++++-------------------------
 src/screenshot-interactive-dialog.c |  13 +--
 src/screenshot-shadow.c             |  12 +--
 src/screenshot-utils.c              |  42 ++++------
 9 files changed, 112 insertions(+), 272 deletions(-)
---
diff --git a/src/gnome-screenshot.c b/src/gnome-screenshot.c
index 9956090..a18ac21 100644
--- a/src/gnome-screenshot.c
+++ b/src/gnome-screenshot.c
@@ -36,8 +36,7 @@
 int
 main (int argc, char *argv[])
 {
-  gint result;
-  ScreenshotApplication *app;
+  g_autoptr(GApplication) app;
 
   setlocale (LC_ALL, "");
   bindtextdomain (GETTEXT_PACKAGE, LOCALEDIR);
@@ -45,8 +44,5 @@ main (int argc, char *argv[])
   textdomain (GETTEXT_PACKAGE);
 
   app = screenshot_application_new ();
-  result = g_application_run (G_APPLICATION (app), argc, argv);
-  g_object_unref (app);
-
-  return result;
+  return g_application_run (app, argc, argv);
 }
diff --git a/src/screenshot-application.c b/src/screenshot-application.c
index bbe2d30..92134ab 100644
--- a/src/screenshot-application.c
+++ b/src/screenshot-application.c
@@ -60,22 +60,18 @@ struct _ScreenshotApplicationPriv {
 static void
 save_folder_to_settings (ScreenshotApplication *self)
 {
-  char *folder;
-
-  folder = screenshot_dialog_get_folder (self->priv->dialog);
+  g_autofree gchar *folder = screenshot_dialog_get_folder (self->priv->dialog);
   g_settings_set_string (screenshot_config->settings,
                          LAST_SAVE_DIRECTORY_KEY, folder);
-
-  g_free (folder);
 }
 
 static void
 set_recent_entry (ScreenshotApplication *self)
 {
-  char *app_exec = NULL;
+  g_autofree gchar *app_exec = NULL;
+  g_autoptr(GAppInfo) app = NULL;
   GtkRecentManager *recent;
   GtkRecentData recent_data;
-  GAppInfo *app;
   const char *exec_name = NULL;
   static char * groups[2] = { "Graphics", NULL };
 
@@ -100,9 +96,6 @@ set_recent_entry (ScreenshotApplication *self)
   recent_data.is_private = FALSE;
 
   gtk_recent_manager_add_full (recent, self->priv->save_uri, &recent_data);
-
-  g_object_unref (app);
-  g_free (app_exec);
 }
 
 static void
@@ -142,25 +135,18 @@ save_pixbuf_handle_error (ScreenshotApplication *self,
       if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_EXISTS) &&
           !self->priv->should_overwrite)
         {
-          gchar *folder = screenshot_dialog_get_folder (dialog);
-          gchar *folder_uri = g_path_get_basename (folder);
-          gchar *folder_name = g_uri_unescape_string (folder_uri, NULL);
-          gchar *file_name = screenshot_dialog_get_filename (dialog);
-          gchar *detail = g_strdup_printf (_("A file named “%s” already exists in “%s”"),
-                                           file_name, folder_name);
-          gint response;
-
-          response = screenshot_show_dialog (GTK_WINDOW (dialog->dialog),
-                                             GTK_MESSAGE_WARNING,
-                                             GTK_BUTTONS_YES_NO,
-                                             _("Overwrite existing file?"),
-                                             detail);
-
-          g_free (folder);
-          g_free (folder_uri);
-          g_free (folder_name);
-          g_free (file_name);
-          g_free (detail);
+          g_autofree gchar *folder = screenshot_dialog_get_folder (dialog);
+          g_autofree gchar *folder_uri = g_path_get_basename (folder);
+          g_autofree gchar *folder_name = g_uri_unescape_string (folder_uri, NULL);
+          g_autofree gchar *file_name = screenshot_dialog_get_filename (dialog);
+          g_autofree gchar *detail = g_strdup_printf (_("A file named “%s” already exists in “%s”"),
+                                                      file_name, folder_name);
+
+          gint response = screenshot_show_dialog (GTK_WINDOW (dialog->dialog),
+                                                  GTK_MESSAGE_WARNING,
+                                                  GTK_BUTTONS_YES_NO,
+                                                  _("Overwrite existing file?"),
+                                                  detail);
 
           if (response == GTK_RESPONSE_YES)
             {
@@ -196,7 +182,7 @@ save_pixbuf_ready_cb (GObject *source,
                       GAsyncResult *res,
                       gpointer user_data)
 {
-  GError *error = NULL;
+  g_autoptr(GError) error = NULL;
   ScreenshotApplication *self = user_data;
 
   gdk_pixbuf_save_to_stream_finish (res, &error);
@@ -204,7 +190,6 @@ save_pixbuf_ready_cb (GObject *source,
   if (error != NULL)
     {
       save_pixbuf_handle_error (self, error);
-      g_error_free (error);
       return;
     }
 
@@ -217,29 +202,20 @@ find_out_writable_format_by_extension (gpointer data,
 {
   GdkPixbufFormat *format     = (GdkPixbufFormat*) data;
   gchar          **name       = (gchar **) user_data;
-  gchar          **extensions = gdk_pixbuf_format_get_extensions (format);
+  g_auto(GStrv)    extensions = gdk_pixbuf_format_get_extensions (format);
   gchar          **ptr        = extensions;
-  gboolean         found      = FALSE;
 
   while (*ptr != NULL)
     {
       if (g_strcmp0 (*ptr, *name) == 0 &&
           gdk_pixbuf_format_is_writable (format) == TRUE)
         {
+          g_free (*name);
           *name = gdk_pixbuf_format_get_name (format);
-          found = TRUE;
           break;
         }
       ptr++;
     }
-
-  g_strfreev (extensions);
-
-  /* Needing to duplicate string here because
-   * gdk_pixbuf_format_get_name will return a duplicated string.
-   */
-  if (!found)
-    *name = g_strdup (*name);
 }
 
 static gboolean
@@ -304,11 +280,11 @@ save_file_create_ready_cb (GObject *source,
                            gpointer user_data)
 {
   ScreenshotApplication *self = user_data;
-  GFileOutputStream *os;
-  GError *error = NULL;
-  gchar *basename = g_file_get_basename (G_FILE (source));
+  g_autoptr(GFileOutputStream) os = NULL;
+  g_autoptr(GError) error = NULL;
+  g_autofree gchar *basename = g_file_get_basename (G_FILE (source));
+  g_autofree gchar *format = NULL;
   gchar *extension = g_strrstr (basename, ".");
-  gchar *format = NULL;
   GSList *formats = NULL;
 
   if (extension == NULL)
@@ -316,14 +292,13 @@ save_file_create_ready_cb (GObject *source,
   else
     extension++;
 
-  format = extension;
+  format = g_strdup (extension);
 
   formats = gdk_pixbuf_get_formats();
   g_slist_foreach (formats,
                    find_out_writable_format_by_extension,
                    (gpointer) &format);
   g_slist_free (formats);
-  g_free (basename);
 
   if (self->priv->should_overwrite)
     os = g_file_replace_finish (G_FILE (source), res, &error);
@@ -333,7 +308,6 @@ save_file_create_ready_cb (GObject *source,
   if (error != NULL)
     {
       save_pixbuf_handle_error (self, error);
-      g_error_free (error);
       return;
     }
 
@@ -348,15 +322,12 @@ save_file_create_ready_cb (GObject *source,
     {
       save_with_no_profile_or_description (self, os, format);
     }
-
-  g_object_unref (os);
-  g_free (format);
 }
 
 static void
 screenshot_save_to_file (ScreenshotApplication *self)
 {
-  GFile *target_file;
+  g_autoptr(GFile) target_file = NULL;
 
   if (self->priv->dialog != NULL)
     screenshot_dialog_set_busy (self->priv->dialog, TRUE);
@@ -380,8 +351,6 @@ screenshot_save_to_file (ScreenshotApplication *self)
                            NULL,
                            save_file_create_ready_cb, self);
     }
-
-  g_object_unref (target_file);
 }
 
 static void
@@ -431,19 +400,13 @@ build_filename_ready_cb (GObject *source,
                          gpointer user_data)
 {
   ScreenshotApplication *self = user_data;
-  GError *error = NULL;
-  char *save_path;
+  g_autoptr(GError) error = NULL;
+  g_autofree gchar *save_path = screenshot_build_filename_finish (res, &error);
 
-  save_path = screenshot_build_filename_finish (res, &error);
   if (save_path != NULL)
     {
-      GFile *file;
-
-      file = g_file_new_for_path (save_path);
-      g_free (save_path);
-
+      g_autoptr(GFile) file = g_file_new_for_path (save_path);
       self->priv->save_uri = g_file_get_uri (file);
-      g_object_unref (file);
     }
   else
     self->priv->save_uri = NULL;
@@ -455,7 +418,6 @@ build_filename_ready_cb (GObject *source,
     {
       g_critical ("Impossible to find a valid location to save the screenshot: %s",
                   error->message);
-      g_error_free (error);
 
       if (screenshot_config->interactive)
         screenshot_show_dialog (NULL,
@@ -828,8 +790,8 @@ static GActionEntry action_entries[] = {
 static void
 screenshot_application_startup (GApplication *app)
 {
-  GMenuModel *menu;
-  GtkBuilder *builder;
+  g_autoptr(GMenuModel) menu = NULL;
+  g_autoptr(GtkBuilder) builder = NULL;
   ScreenshotApplication *self = SCREENSHOT_APPLICATION (app);
 
   G_APPLICATION_CLASS (screenshot_application_parent_class)->startup (app);
@@ -846,9 +808,6 @@ screenshot_application_startup (GApplication *app)
   gtk_builder_add_from_resource (builder, "/org/gnome/screenshot/screenshot-app-menu.ui", NULL);
   menu = G_MENU_MODEL (gtk_builder_get_object (builder, "app-menu"));
   gtk_application_set_app_menu (GTK_APPLICATION (app), menu);
-
-  g_object_unref (builder);
-  g_object_unref (menu);
 }
 
 static void
@@ -904,7 +863,7 @@ screenshot_application_init (ScreenshotApplication *self)
   g_application_add_main_option_entries (G_APPLICATION (self), entries);
 }
 
-ScreenshotApplication *
+GApplication *
 screenshot_application_new (void)
 {
   return g_object_new (SCREENSHOT_TYPE_APPLICATION,
diff --git a/src/screenshot-application.h b/src/screenshot-application.h
index 3b6fe93..59287eb 100644
--- a/src/screenshot-application.h
+++ b/src/screenshot-application.h
@@ -49,6 +49,6 @@ typedef struct {
 } ScreenshotApplicationClass;
 
 GType screenshot_application_get_type (void);
-ScreenshotApplication * screenshot_application_new (void);
+GApplication * screenshot_application_new (void);
 
 #endif /* __SCREENSHOT_APPLICATION_H__ */
diff --git a/src/screenshot-area-selection.c b/src/screenshot-area-selection.c
index 820b88b..713e4b2 100644
--- a/src/screenshot-area-selection.c
+++ b/src/screenshot-area-selection.c
@@ -226,8 +226,8 @@ emit_select_callback_in_idle (gpointer user_data)
 static void
 screenshot_select_area_x11_async (CallbackData *cb_data)
 {
+  g_autoptr(GdkCursor) cursor = NULL;
   GdkDisplay *display;
-  GdkCursor *cursor;
   select_area_filter_data  data;
   GdkDeviceManager *manager;
   GdkDevice *pointer, *keyboard;
@@ -260,10 +260,7 @@ screenshot_select_area_x11_async (CallbackData *cb_data)
                          cursor, GDK_CURRENT_TIME);
 
   if (res != GDK_GRAB_SUCCESS)
-    {
-      g_object_unref (cursor);
-      goto out;
-    }
+    goto out;
 
   res = gdk_device_grab (keyboard, gtk_widget_get_window (data.window),
                          GDK_OWNERSHIP_NONE, FALSE,
@@ -273,7 +270,6 @@ screenshot_select_area_x11_async (CallbackData *cb_data)
   if (res != GDK_GRAB_SUCCESS)
     {
       gdk_device_ungrab (pointer, GDK_CURRENT_TIME);
-      g_object_unref (cursor);
       goto out;
     }
 
@@ -283,8 +279,6 @@ screenshot_select_area_x11_async (CallbackData *cb_data)
   gdk_device_ungrab (keyboard, GDK_CURRENT_TIME);
 
   gtk_widget_destroy (data.window);
-  g_object_unref (cursor);
-
   gdk_flush ();
 
  out:
@@ -304,15 +298,14 @@ select_area_done (GObject *source_object,
                   gpointer user_data)
 {
   CallbackData *cb_data = user_data;
-  GError *error = NULL;
-  GVariant *ret;
+  g_autoptr(GError) error = NULL;
+  g_autoptr(GVariant) ret = NULL;
 
   ret = g_dbus_connection_call_finish (G_DBUS_CONNECTION (source_object), res, &error);
   if (error != NULL)
     {
       if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
         {
-          g_error_free (error);
           cb_data->aborted = TRUE;
           g_idle_add (emit_select_callback_in_idle, cb_data);
           return;
@@ -320,7 +313,6 @@ select_area_done (GObject *source_object,
 
       g_message ("Unable to select area using GNOME Shell's builtin screenshot "
                  "interface, resorting to fallback X11.");
-      g_error_free (error);
 
       screenshot_select_area_x11_async (cb_data);
       return;
@@ -331,7 +323,6 @@ select_area_done (GObject *source_object,
                  &cb_data->rectangle.y,
                  &cb_data->rectangle.width,
                  &cb_data->rectangle.height);
-  g_variant_unref (ret);
 
   g_idle_add (emit_select_callback_in_idle, cb_data);
 }
diff --git a/src/screenshot-dialog.c b/src/screenshot-dialog.c
index 76757d2..9527b77 100644
--- a/src/screenshot-dialog.c
+++ b/src/screenshot-dialog.c
@@ -202,14 +202,12 @@ screenshot_dialog_new (GdkPixbuf              *screenshot,
                        SaveScreenshotCallback f,
                        gpointer               user_data)
 {
+  g_autoptr(GFile) tmp_file = NULL, parent_file = NULL;
+  g_autoptr(GtkBuilder) ui = NULL;
+  g_autofree gchar *current_folder = NULL, *current_name = NULL;
   ScreenshotDialog *dialog;
-  GtkBuilder *ui;
-  char *current_folder;
-  char *current_name;
   char *ext;
   gint pos;
-  GFile *tmp_file;
-  GFile *parent_file;
   guint res;
 
   tmp_file = g_file_new_for_uri (initial_uri);
@@ -217,8 +215,6 @@ screenshot_dialog_new (GdkPixbuf              *screenshot,
 
   current_name = g_file_get_basename (tmp_file);
   current_folder = g_file_get_uri (parent_file);
-  g_object_unref (tmp_file);
-  g_object_unref (parent_file);
 
   dialog = g_new0 (ScreenshotDialog, 1);
   dialog->screenshot = screenshot;
@@ -266,30 +262,19 @@ screenshot_dialog_new (GdkPixbuf              *screenshot,
                               0,
                               pos);
 
-  g_free (current_name);
-  g_free (current_folder);
-  g_object_unref (ui);
-
   return dialog;
 }
 
 char *
 screenshot_dialog_get_uri (ScreenshotDialog *dialog)
 {
-  gchar *folder, *file;
-  gchar *uri;
-  gchar *tmp;
+  g_autofree gchar *folder = NULL, *file = NULL, *tmp = NULL;
 
   folder = gtk_file_chooser_get_uri (GTK_FILE_CHOOSER (dialog->save_widget));
   tmp = screenshot_dialog_get_filename (dialog);
   file = g_uri_escape_string (tmp, NULL, FALSE);
-  g_free (tmp);
-  uri = g_build_filename (folder, file, NULL);
-
-  g_free (folder);
-  g_free (file);
 
-  return uri;
+  return g_build_filename (folder, file, NULL);
 }
 
 char *
@@ -301,21 +286,19 @@ screenshot_dialog_get_folder (ScreenshotDialog *dialog)
 char *
 screenshot_dialog_get_filename (ScreenshotDialog *dialog)
 {
+  g_autoptr(GError) error = NULL;
   const gchar *file_name;
   gchar *tmp;
-  GError *error;
 
   file_name = gtk_entry_get_text (GTK_ENTRY (dialog->filename_entry));
-
-  error = NULL;
   tmp = g_filename_from_utf8 (file_name, -1, NULL, NULL, &error);
-  if (error)
+
+  if (error != NULL)
     {
       g_warning ("Unable to convert `%s' to valid UTF-8: %s\n"
                  "Falling back to default file.",
                  file_name,
                  error->message);
-      g_error_free (error);
       tmp = g_strdup (_("Screenshot.png"));
     }
 
@@ -332,13 +315,12 @@ screenshot_dialog_set_busy (ScreenshotDialog *dialog,
 
   if (busy)
     {
+      g_autoptr(GdkCursor) cursor = NULL;
       GdkDisplay *display;
-      GdkCursor *cursor;
       /* Change cursor to busy */
       display = gtk_widget_get_display (GTK_WIDGET (dialog));
       cursor = gdk_cursor_new_for_display (display, GDK_WATCH);
       gdk_window_set_cursor (window, cursor);
-      g_object_unref (cursor);
     }
   else
     {
diff --git a/src/screenshot-filename-builder.c b/src/screenshot-filename-builder.c
index 86c1a51..5fbd482 100644
--- a/src/screenshot-filename-builder.c
+++ b/src/screenshot-filename-builder.c
@@ -48,7 +48,8 @@ typedef struct
 static char *
 expand_initial_tilde (const char *path)
 {
-  char *slash_after_user_name, *user_name;
+  g_autofree gchar *user_name = NULL;
+  char *slash_after_user_name;
   struct passwd *passwd_file_entry;
 
   if (path[1] == '/' || path[1] == '\0') {
@@ -63,7 +64,6 @@ expand_initial_tilde (const char *path)
                            slash_after_user_name - &path[1]);
   }
   passwd_file_entry = getpwnam (user_name);
-  g_free (user_name);
 
   if (passwd_file_entry == NULL || passwd_file_entry->pw_dir == NULL) {
     return g_strdup (path);
@@ -89,35 +89,26 @@ get_default_screenshot_dir (void)
 static gchar *
 sanitize_save_directory (const gchar *save_dir)
 {
-  gchar *retval = g_strdup (save_dir);
-
   if (save_dir == NULL)
     return NULL;
 
   if (save_dir[0] == '~')
-    {
-      char *tmp = expand_initial_tilde (save_dir);
-      g_free (retval);
-      retval = tmp;
-    }
-  else if (strstr (save_dir, "://") != NULL)
-    {
-      GFile *file;
+    return expand_initial_tilde (save_dir);
 
-      g_free (retval);
-      file = g_file_new_for_uri (save_dir);
-      retval = g_file_get_path (file);
-      g_object_unref (file);
+  if (strstr (save_dir, "://") != NULL)
+    {
+      g_autoptr(GFile) file = g_file_new_for_uri (save_dir);
+      return g_file_get_path (file);
     }
 
-  return retval;
+  return g_strdup (save_dir);
 }
 
 static char *
 build_path (AsyncExistenceJob *job)
 {
+  g_autofree gchar *file_name = NULL, *origin = NULL;
   const gchar *base_path, *file_type;
-  char *retval, *file_name, *origin;
 
   base_path = job->base_paths[job->type];
   file_type = screenshot_config->file_type;
@@ -128,11 +119,8 @@ build_path (AsyncExistenceJob *job)
 
   if (job->screenshot_origin == NULL)
     {
-      GDateTime *d;
-
-      d = g_date_time_new_now_local ();
+      g_autoptr(GDateTime) d = g_date_time_new_now_local ();
       origin = g_date_time_format (d, "%Y-%m-%d %H-%M-%S");
-      g_date_time_unref (d);
     }
   else
     origin = g_strdup (job->screenshot_origin);
@@ -157,11 +145,7 @@ build_path (AsyncExistenceJob *job)
       file_name = g_strdup_printf (_("Screenshot from %s - %d.%s"), origin, job->iteration, file_type);
     }
 
-  retval = g_build_filename (base_path, file_name, NULL);
-  g_free (file_name);
-  g_free (origin);
-
-  return retval;
+  return g_build_filename (base_path, file_name, NULL);
 }
 
 static void
@@ -200,104 +184,56 @@ try_check_file (GTask *task,
                 GCancellable *cancellable)
 {
   AsyncExistenceJob *job = data;
-  GFile *file;
-  GFileInfo *info;
-  GError *error;
-  char *path, *retval;
 
-retry:
-  error = NULL;
-  path = build_path (job);
-
-  if (path == NULL)
+  while (TRUE)
     {
-      (job->type)++;
-      goto retry;
-    }
+      g_autoptr(GError) error = NULL;
+      g_autoptr(GFile) file = NULL;
+      g_autoptr(GFileInfo) info = NULL;
+      g_autofree gchar *path = build_path (job);
 
-  file = g_file_new_for_path (path);
-  info = g_file_query_info (file, G_FILE_ATTRIBUTE_STANDARD_TYPE,
-                            G_FILE_QUERY_INFO_NONE, cancellable, &error);
-  if (info != NULL)
-    {
-      /* file already exists, iterate again */
-      g_object_unref (info);
-      g_object_unref (file);
-      g_free (path);
+      if (path == NULL)
+        {
+          (job->type)++;
+          continue;
+        }
 
-      (job->iteration)++;
+      file = g_file_new_for_path (path);
+      info = g_file_query_info (file, G_FILE_ATTRIBUTE_STANDARD_TYPE,
+                                G_FILE_QUERY_INFO_NONE, cancellable, &error);
+      if (info != NULL)
+        {
+          /* file already exists, iterate again */
+          (job->iteration)++;
+          continue;
+        }
 
-      goto retry;
-    }
-  else
-    {
       /* see the error to check whether the location is not accessible
        * or the file does not exist.
        */
-      if (error->code == G_IO_ERROR_NOT_FOUND)
+      if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND))
         {
-          GFile *parent;
+          g_autoptr(GFile) parent = g_file_get_parent (file);
 
-          /* if the parent directory doesn't exist as well, forget the saved
+          /* if the parent directory doesn't exist as well, we'll forget the saved
            * directory and treat this as a generic error.
            */
-
-          parent = g_file_get_parent (file);
-
-          if (!g_file_query_exists (parent, NULL))
+          if (g_file_query_exists (parent, NULL))
             {
-              if (!prepare_next_cycle (job))
-                {
-                  retval = NULL;
-
-                  g_object_unref (parent);
-                  goto out;
-                }
-
-              g_object_unref (file);
-              g_object_unref (parent);
-              goto retry;
-            }
-          else
-            {
-              retval = path;
-
-              g_object_unref (parent);
-              goto out;
+              g_task_return_pointer (task, g_steal_pointer (&path), NULL);
+              return;
             }
         }
-      else
-        {
-          /* another kind of error, assume this location is not
-           * accessible.
-           */
-          g_free (path);
 
-          if (prepare_next_cycle (job))
-            {
-              g_error_free (error);
-              g_object_unref (file);
-              goto retry;
-            }
-          else
-            {
-              retval = NULL;
-              goto out;
-            }
+      if (!prepare_next_cycle (job))
+        {
+          g_task_return_new_error (task,
+                                   G_IO_ERROR,
+                                   G_IO_ERROR_FAILED,
+                                   "%s", "Failed to find a valid place to save");
+          return;
         }
     }
-
-out:
-  g_error_free (error);
-  g_object_unref (file);
-
-  if (retval == NULL)
-    g_task_return_new_error (task,
-                             G_IO_ERROR,
-                             G_IO_ERROR_FAILED,
-                             "%s", "Failed to find a valid place to save");
-
-  g_task_return_pointer (task, retval, NULL);
 }
 
 void
@@ -307,7 +243,7 @@ screenshot_build_filename_async (const char *save_dir,
                                  gpointer user_data)
 {
   AsyncExistenceJob *job;
-  GTask *task;
+  g_autoptr(GTask) task = NULL;
 
   job = g_slice_new0 (AsyncExistenceJob);
 
@@ -323,7 +259,6 @@ screenshot_build_filename_async (const char *save_dir,
   g_task_set_task_data (task, job, (GDestroyNotify) async_existence_job_free);
 
   g_task_run_in_thread (task, try_check_file);
-  g_object_unref (task);
 }
 
 gchar *
diff --git a/src/screenshot-interactive-dialog.c b/src/screenshot-interactive-dialog.c
index dd50c3c..e24552e 100644
--- a/src/screenshot-interactive-dialog.c
+++ b/src/screenshot-interactive-dialog.c
@@ -163,8 +163,8 @@ static guint n_effects = G_N_ELEMENTS (effects);
 static GtkWidget *
 create_effects_combo (void)
 {
+  g_autoptr(GtkListStore) model = NULL;
   GtkWidget *retval;
-  GtkListStore *model;
   GtkCellRenderer *renderer;
   gint i;
 
@@ -188,7 +188,6 @@ create_effects_combo (void)
   retval = gtk_combo_box_new ();
   gtk_combo_box_set_model (GTK_COMBO_BOX (retval),
                            GTK_TREE_MODEL (model));
-  g_object_unref (model);
 
   switch (screenshot_config->border_effect[0])
     {
@@ -233,7 +232,7 @@ create_effects_frame (GtkWidget   *outer_vbox,
   GtkWidget *label;
   GtkWidget *check;
   GtkWidget *combo;
-  gchar *title;
+  g_autofree gchar *title = NULL;
 
   main_vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 6);
   gtk_box_pack_start (GTK_BOX (outer_vbox), main_vbox, FALSE, FALSE, 0);
@@ -247,7 +246,6 @@ create_effects_frame (GtkWidget   *outer_vbox,
   gtk_widget_set_valign (label, GTK_ALIGN_CENTER);
   gtk_box_pack_start (GTK_BOX (main_vbox), label, FALSE, FALSE, 0);
   gtk_widget_show (label);
-  g_free (title);
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 12);
   gtk_box_pack_start (GTK_BOX (main_vbox), hbox, FALSE, FALSE, 0);
@@ -313,7 +311,7 @@ create_screenshot_frame (GtkWidget   *outer_vbox,
   GtkWidget *label;
   GtkAdjustment *adjust;
   GSList *group;
-  gchar *title;
+  g_autofree gchar *title = NULL;
 
   main_vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 6);
   gtk_box_pack_start (GTK_BOX (outer_vbox), main_vbox, FALSE, FALSE, 0);
@@ -326,7 +324,6 @@ create_screenshot_frame (GtkWidget   *outer_vbox,
   gtk_widget_set_valign (label, GTK_ALIGN_CENTER);
   gtk_box_pack_start (GTK_BOX (main_vbox), label, FALSE, FALSE, 0);
   gtk_widget_show (label);
-  g_free (title);
 
   hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 12);
   gtk_box_pack_start (GTK_BOX (main_vbox), hbox, FALSE, FALSE, 0);
@@ -439,7 +436,7 @@ screenshot_interactive_dialog_new (CaptureClickedCallback f, gpointer user_data)
   GtkWidget *header_bar;
   GtkWidget *button;
   GtkStyleContext *context;
-  GtkSizeGroup *size_group;
+  g_autoptr(GtkSizeGroup) size_group = NULL;
   CaptureData *data;
 
   dialog = gtk_application_window_new (GTK_APPLICATION (g_application_get_default ()));
@@ -488,8 +485,6 @@ screenshot_interactive_dialog_new (CaptureClickedCallback f, gpointer user_data)
   g_signal_connect_swapped (button, "clicked",
                             G_CALLBACK (gtk_widget_destroy), dialog);
 
-  g_object_unref (size_group);
-
   gtk_widget_show_all (dialog);
 
   return dialog;
diff --git a/src/screenshot-shadow.c b/src/screenshot-shadow.c
index db0c891..f377f98 100644
--- a/src/screenshot-shadow.c
+++ b/src/screenshot-shadow.c
@@ -208,8 +208,7 @@ screenshot_add_shadow (GdkPixbuf **src)
                         gdk_pixbuf_get_height (*src),
                         BLUR_RADIUS, BLUR_RADIUS, 1.0, 1.0,
                         GDK_INTERP_BILINEAR, 255);
-  g_object_unref (*src);
-  *src = dest;
+  g_set_object (src, dest);
 }
 
 void
@@ -234,8 +233,7 @@ screenshot_add_border (GdkPixbuf **src)
                         gdk_pixbuf_get_height (*src),
                         OUTLINE_RADIUS, OUTLINE_RADIUS, 1.0, 1.0,
                         GDK_INTERP_BILINEAR, 255);
-  g_object_unref (*src);
-  *src = dest;
+  g_set_object (src, dest);
 }
 
 void
@@ -261,8 +259,7 @@ screenshot_add_vintage (GdkPixbuf **src)
                         gdk_pixbuf_get_height (*src),
                         VINTAGE_OUTLINE_RADIUS, VINTAGE_OUTLINE_RADIUS, 1.0, 1.0,
                         GDK_INTERP_HYPER, 255);
-  g_object_unref (*src);
-  *src = dest;
+  g_set_object (src, dest);
 
   gdk_pixbuf_saturate_and_pixelate (*src, *src,
                                     VINTAGE_SATURATION, FALSE);
@@ -276,6 +273,5 @@ screenshot_add_vintage (GdkPixbuf **src)
   if (dest == NULL)
     return;
 
-  g_object_unref (*src);
-  *src = dest;
+  g_set_object (src, dest);
 }
diff --git a/src/screenshot-utils.c b/src/screenshot-utils.c
index b62bf26..261fd71 100644
--- a/src/screenshot-utils.c
+++ b/src/screenshot-utils.c
@@ -381,7 +381,7 @@ static GdkPixbuf *
 screenshot_fallback_get_pixbuf (GdkRectangle *rectangle)
 {
   GdkWindow *root, *wm_window = NULL;
-  GdkPixbuf *screenshot;
+  GdkPixbuf *screenshot = NULL;
   GdkRectangle real_coords, screenshot_coords;
   Window wm;
   GtkBorder frame_offset = { 0, 0, 0, 0 };
@@ -434,7 +434,6 @@ screenshot_fallback_get_pixbuf (GdkRectangle *rectangle)
   if (screenshot_config->include_border && (wm != None))
     {
       XRectangle *rectangles;
-      GdkPixbuf *tmp;
       int rectangle_count, rectangle_order, i;
 
       /* we must use XShape to avoid showing what's under the rounder corners
@@ -448,9 +447,8 @@ screenshot_fallback_get_pixbuf (GdkRectangle *rectangle)
       if (rectangles && rectangle_count > 0)
         {
           gboolean has_alpha = gdk_pixbuf_get_has_alpha (screenshot);
-
-          tmp = gdk_pixbuf_new (GDK_COLORSPACE_RGB, TRUE, 8,
-                                screenshot_coords.width, screenshot_coords.height);
+          GdkPixbuf *tmp = gdk_pixbuf_new (GDK_COLORSPACE_RGB, TRUE, 8,
+                                           screenshot_coords.width, screenshot_coords.height);
           gdk_pixbuf_fill (tmp, 0);
 
           for (i = 0; i < rectangle_count; i++)
@@ -516,8 +514,7 @@ screenshot_fallback_get_pixbuf (GdkRectangle *rectangle)
                 }
             }
 
-          g_object_unref (screenshot);
-          screenshot = tmp;
+          g_set_object (&screenshot, tmp);
 
           XFree (rectangles);
         }
@@ -528,8 +525,8 @@ screenshot_fallback_get_pixbuf (GdkRectangle *rectangle)
    * screenshot */
   if (screenshot_config->include_pointer && !rectangle)
     {
-      GdkCursor *cursor;
-      GdkPixbuf *cursor_pixbuf;
+      g_autoptr(GdkCursor) cursor = NULL;
+      g_autoptr(GdkPixbuf) cursor_pixbuf = NULL;
 
       cursor = gdk_cursor_new_for_display (gdk_display_get_default (), GDK_LEFT_PTR);
       cursor_pixbuf = gdk_cursor_get_image (cursor);
@@ -575,9 +572,6 @@ screenshot_fallback_get_pixbuf (GdkRectangle *rectangle)
                                     GDK_INTERP_BILINEAR,
                                     255);
             }
-
-          g_object_unref (cursor_pixbuf);
-          g_object_unref (cursor);
         }
     }
 
@@ -589,11 +583,11 @@ screenshot_fallback_get_pixbuf (GdkRectangle *rectangle)
 GdkPixbuf *
 screenshot_get_pixbuf (GdkRectangle *rectangle)
 {
+  g_autoptr(GError) error = NULL;
+  g_autofree gchar *path = NULL, *filename = NULL, *tmpname = NULL;
   GdkPixbuf *screenshot = NULL;
-  gchar *path, *filename, *tmpname;
   const gchar *method_name;
   GVariant *method_params;
-  GError *error = NULL;
   GDBusConnection *connection;
 
   path = g_build_filename (g_get_user_cache_dir (), "gnome-screenshot", NULL);
@@ -654,15 +648,10 @@ screenshot_get_pixbuf (GdkRectangle *rectangle)
     {
       g_message ("Unable to use GNOME Shell's builtin screenshot interface, "
                  "resorting to fallback X11.");
-      g_error_free (error);
 
       screenshot = screenshot_fallback_get_pixbuf (rectangle);
     }
 
-  g_free (path);
-  g_free (tmpname);
-  g_free (filename);
-
   return screenshot;
 }
 
@@ -709,19 +698,16 @@ screenshot_show_dialog (GtkWindow   *parent,
 void
 screenshot_display_help (GtkWindow *parent)
 {
-  GError *error = NULL;
+  g_autoptr(GError) error = NULL;
 
   gtk_show_uri (gtk_window_get_screen (parent),
                 "help:gnome-help/screen-shot-record",
                 gtk_get_current_event_time (), &error);
 
   if (error)
-    {
-      screenshot_show_dialog (parent,
-                              GTK_MESSAGE_ERROR,
-                              GTK_BUTTONS_OK,
-                              _("Error loading the help page"),
-                              error->message);
-      g_error_free (error);
-    }
+    screenshot_show_dialog (parent,
+                            GTK_MESSAGE_ERROR,
+                            GTK_BUTTONS_OK,
+                            _("Error loading the help page"),
+                            error->message);
 }