* lisp/mouse.el (mouse-drag-and-drop-region): Use 'car-safe'
instead of 'car' to ignore 'select-window' events. Thanks to
Stefan Monnier for spotting this.
(setq event (read-event))
(or (mouse-movement-p event)
;; Handle `mouse-autoselect-window'.
- (eq (car event) 'select-window)))
+ (eq (car-safe event) 'select-window)))
(unless value-selection ; initialization
(delete-overlay mouse-secondary-overlay)
(setq value-selection (buffer-substring start end))