So shortcut it.
I wrote this patch less as a performance optimization and more as a
clarification, so that people looking at the code can be assured of this
invariant.
https://bugzilla.gnome.org/show_bug.cgi?id=738374
g_return_val_if_fail (G_IS_FILE (file1), FALSE);
g_return_val_if_fail (G_IS_FILE (file2), FALSE);
+ if (file1 == file2)
+ return TRUE;
+
if (G_TYPE_FROM_INSTANCE (file1) != G_TYPE_FROM_INSTANCE (file2))
return FALSE;