+ /* When we restore a window's configuration, the identity of
+ the window hasn't actually changed - so there is no
+ reason why we shouldn't preserve the instance cache for
+ it - unless it was originally deleted. This will often
+ buy us something as we will not have to re-instantiate
+ all the instances. This is because this is an instance
+ cache - not a display cache. Preserving the display cache
+ would definitely be wrong.
+
+ We specifically want to do this for tabs, since for some
+ reason finding a file will cause the configuration to be
+ set. */
+ if (NILP (w->subwindow_instance_cache))
+ w->subwindow_instance_cache =
+ make_lisp_hash_table (30,
+ HASH_TABLE_KEY_VALUE_WEAK,
+ HASH_TABLE_EQ);