is non-nil it is silently bashed; else if the function was
called interactively the user is queried as to whether s/he
wants to bash the file; otherwise (ok-if-exists nil, non-interactive)
- a file-already-exists error is signalled.
+ a file-already-exists error is signaled.
* window.c: Made get-window-buffer return nil if get-buffer of
its arg returns nil, rather than erring.