[gnome-photos/gnome-3-12] facebook-item: Handle failures gracefully without aborting

[Debarshi Ray <debarshir src gnome org>]

commit b01ba286309dffc88f3a530de93e8b138d064ba5
Author: Debarshi Ray <debarshir gnome org>
Date:   Tue Apr 15 15:13:56 2014 +0200

    facebook-item: Handle failures gracefully without aborting
    
    Each failure should be represented by setting the GError **, which
    should be bubbled up to the caller. Use gotos and properly initialized
    variables to clean up resources on both the error and success code
    paths.
    
    In case we failed to download an item, clean up the leftover local
    file.
    
    Fixes: https://bugzilla.gnome.org/727205

 src/photos-facebook-item.c |  158 ++++++++++++++++++++++----------------------
 1 files changed, 78 insertions(+), 80 deletions(-)
---
diff --git a/src/photos-facebook-item.c b/src/photos-facebook-item.c
index 4cc0f8b..c0acf02 100644
--- a/src/photos-facebook-item.c
+++ b/src/photos-facebook-item.c
@@ -79,50 +79,46 @@ photos_facebook_item_create_thumbnail (PhotosBaseItem *item, GCancellable *cance
 {
   GFBGraphPhoto *photo;
   const GFBGraphPhotoImage *thumbnail_image;
-  gchar *local_path, *local_dir;
-  GFile *local_file, *remote_file;
+  gchar *local_path = NULL, *local_dir = NULL;
+  GFile *local_file = NULL, *remote_file = NULL;
   gboolean ret_val = FALSE;
 
   photo = photos_facebook_get_gfbgraph_photo (item, cancellable, error);
   if (photo == NULL)
+    goto out;
+
+  thumbnail_image = gfbgraph_photo_get_image_near_width (photo, photos_utils_get_icon_size ());
+  if (thumbnail_image == NULL)
     {
-      g_error ("Can't get the photo from the Facebook Graph\n");
-    }
-  else
-    {
-    thumbnail_image = gfbgraph_photo_get_image_near_width (photo, photos_utils_get_icon_size ());
-    if (thumbnail_image == NULL)
-      {
-        g_error ("Can't get a photo size to create the thumbnail.\n");
-      }
-    else
-      {
-        remote_file = g_file_new_for_uri (thumbnail_image->source);
-
-        local_path = gnome_desktop_thumbnail_path_for_uri (photos_base_item_get_uri (item),
-                                                           GNOME_DESKTOP_THUMBNAIL_SIZE_NORMAL);
-        local_file = g_file_new_for_path (local_path);
-        local_dir = g_path_get_dirname (local_path);
-        g_mkdir_with_parents (local_dir, 0700);
-
-        g_debug ("Downloading %s from Facebook to %s",
-                 thumbnail_image->source, local_path);
-        if (g_file_copy (remote_file,
-                         local_file,
-                         G_FILE_COPY_ALL_METADATA | G_FILE_COPY_OVERWRITE,
-                         cancellable,
-                         NULL,
-                         NULL,
-                         error))
-          ret_val = TRUE;
-
-        g_free (local_path);
-        g_free (local_dir);
-        g_clear_object (&local_file);
-        g_clear_object (&remote_file);
-      }
+      g_set_error (error, PHOTOS_ERROR, 0, "Failed to find an image for the thumbnail");
+      goto out;
     }
 
+  remote_file = g_file_new_for_uri (thumbnail_image->source);
+
+  local_path = gnome_desktop_thumbnail_path_for_uri (photos_base_item_get_uri (item),
+                                                     GNOME_DESKTOP_THUMBNAIL_SIZE_NORMAL);
+  local_file = g_file_new_for_path (local_path);
+  local_dir = g_path_get_dirname (local_path);
+  g_mkdir_with_parents (local_dir, 0700);
+
+  g_debug ("Downloading %s from Facebook to %s", thumbnail_image->source, local_path);
+  if (!g_file_copy (remote_file,
+                    local_file,
+                    G_FILE_COPY_ALL_METADATA | G_FILE_COPY_OVERWRITE,
+                    cancellable,
+                    NULL,
+                    NULL,
+                    error))
+    goto out;
+
+  ret_val = TRUE;
+
+ out:
+  g_free (local_path);
+  g_free (local_dir);
+  g_clear_object (&local_file);
+  g_clear_object (&remote_file);
   return ret_val;
 }
 
@@ -130,59 +126,61 @@ photos_facebook_item_create_thumbnail (PhotosBaseItem *item, GCancellable *cance
 static gchar *
 photos_facebook_item_download (PhotosBaseItem *item, GCancellable *cancellable, GError **error)
 {
-  GFBGraphPhoto *photo;
+  GFBGraphPhoto *photo = NULL;
   const GFBGraphPhotoImage *higher_image;
   const gchar *identifier;
-  gchar *local_dir, *filename, *local_filename;
-  GFile *local_file, *remote_file;
+  gchar *local_dir = NULL, *filename = NULL, *local_filename = NULL;
+  gchar *ret_val = NULL;
+  GFile *local_file = NULL, *remote_file = NULL;
 
   photo = photos_facebook_get_gfbgraph_photo (item, cancellable, error);
   if (photo == NULL)
+    goto out;
+
+  higher_image = gfbgraph_photo_get_image_hires (photo);
+  if (higher_image == NULL)
     {
-      g_error ("Can't get the photo from the Facebook Graph\n");
+      g_set_error (error, PHOTOS_ERROR, 0, "Failed to find a high resolution image");
+      goto out;
     }
-  else
+
+  remote_file = g_file_new_for_uri (higher_image->source);
+
+  /* Local path */
+  local_dir = g_build_filename (g_get_user_cache_dir (), PACKAGE_TARNAME, "facebook", NULL);
+  g_mkdir_with_parents (local_dir, 0700);
+
+  /* Local filename */
+  identifier = photos_base_item_get_identifier (item) + strlen("facebook:photos:");
+  filename = g_strdup_printf ("%s.jpeg", identifier);
+  local_filename = g_build_filename (local_dir, filename, NULL);
+
+  local_file = g_file_new_for_path (local_filename);
+
+  g_debug ("Downloading %s from Facebook to %s", higher_image->source, local_filename);
+  if (!g_file_copy (remote_file,
+                    local_file,
+                    G_FILE_COPY_ALL_METADATA | G_FILE_COPY_OVERWRITE,
+                    cancellable,
+                    NULL,
+                    NULL,
+                    error))
     {
-      higher_image = gfbgraph_photo_get_image_hires (photo);
-      if (higher_image == NULL)
-        {
-          g_error ("Cant' get the higher photo size from Facebook.\n");
-        }
-      else
-        {
-          remote_file = g_file_new_for_uri (higher_image->source);
-
-          /* Local path */
-          local_dir = g_build_filename (g_get_user_cache_dir (), PACKAGE_TARNAME, "facebook", NULL);
-          g_mkdir_with_parents (local_dir, 0700);
-
-          /* Local filename */
-          identifier = photos_base_item_get_identifier (item) + strlen("facebook:photos:");
-          filename = g_strdup_printf ("%s.jpeg", identifier);
-          local_filename = g_build_filename (local_dir, filename, NULL);
-
-          local_file = g_file_new_for_path (local_filename);
-
-          g_debug ("Downloading %s from Facebook to %s", higher_image->source, local_filename);
-          if (!g_file_copy (remote_file,
-                            local_file,
-                            G_FILE_COPY_ALL_METADATA | G_FILE_COPY_OVERWRITE,
-                            cancellable,
-                            NULL,
-                            NULL,
-                            error))
-            g_warning ("Failed downloading %s from Facebook to %s\n", higher_image->source, local_filename);
-
-          g_free (filename);
-          g_free (local_dir);
-          g_clear_object (&local_file);
-          g_clear_object (&remote_file);
-        }
-
-      g_clear_object (&photo);
+      g_file_delete (local_file, NULL, NULL);
+      goto out;
     }
 
-  return local_filename;
+  ret_val = local_filename;
+  local_filename = NULL;
+
+ out:
+  g_free (local_filename);
+  g_free (filename);
+  g_free (local_dir);
+  g_clear_object (&local_file);
+  g_clear_object (&remote_file);
+  g_clear_object (&photo);
+  return ret_val;
 }