Revert and re-apply badnull patch

Revert previous patch generated by badnull.cocci script, and apply the new one.
The main difference is that assert and assert-like functions are not touched
anymore.




SVN revision: 51650

src/icon_chooser.c

@@ -325,7 +325,7 @@ void update_preview_cb (GtkFileChooser *file_chooser, gpointer data)
       height = 1;
 
     pixbuf = gdk_pixbuf_new_from_file_at_size (filename, width, height, NULL);
-    have_preview = (pixbuf);
+    have_preview = !!pixbuf;
     g_free (filename);
 
     gtk_image_set_from_pixbuf (GTK_IMAGE (preview), pixbuf);