Bug 663955 - Instead of decoding twice, use gdk_pixbuf_get_file_info to get the image width and height; then if either is larger than 180, call gdk_pixbuf_new_from_file_at_size, otherwise call gdk_pixbuf_new_from_file. r=roc

--HG--
extra : transplant_source : n%B2%BC%C2Ov%21%EC%8B%ADF6%DC%DD%19v%B6%E1%97%B8

widget/src/gtk2/nsFilePicker.cpp

@@ -136,19 +136,30 @@ UpdateFilePreviewWidget(GtkFileChooser *file_chooser,
     return;
   }
 
-  // We do this so GTK scales down images that are too big, but not scale up images that are too small
-  GdkPixbuf *preview_pixbuf = gdk_pixbuf_new_from_file(image_filename, NULL);
-  if (!preview_pixbuf) {
+  gint preview_width = 0;
+  gint preview_height = 0;
+  GdkPixbufFormat *preview_format = gdk_pixbuf_get_file_info(image_filename,
+                                                             &preview_width,
+                                                             &preview_height);
+  if (!preview_format) {
     g_free(image_filename);
     gtk_file_chooser_set_preview_widget_active(file_chooser, FALSE);
     return;
   }
-  if (gdk_pixbuf_get_width(preview_pixbuf) > MAX_PREVIEW_SIZE || gdk_pixbuf_get_height(preview_pixbuf) > MAX_PREVIEW_SIZE) {
-    g_object_unref(preview_pixbuf);
-    preview_pixbuf = gdk_pixbuf_new_from_file_at_size(image_filename, MAX_PREVIEW_SIZE, MAX_PREVIEW_SIZE, NULL);
+
+  GdkPixbuf *preview_pixbuf;
+  // Only scale down images that are too big
+  if (preview_width > MAX_PREVIEW_SIZE || preview_height > MAX_PREVIEW_SIZE) {
+    preview_pixbuf = gdk_pixbuf_new_from_file_at_size(image_filename,
+                                                      MAX_PREVIEW_SIZE,
+                                                      MAX_PREVIEW_SIZE, NULL);
+  }
+  else {
+    preview_pixbuf = gdk_pixbuf_new_from_file(image_filename, NULL);
   }
 
   g_free(image_filename);
+
   if (!preview_pixbuf) {
     gtk_file_chooser_set_preview_widget_active(file_chooser, FALSE);
     return;