inhibit-field-text-motion to t so rectangles work in comint buffers.
;; Rectangle is padded if PAD = t or numeric and (cua--rectangle-virtual-edges)
;; Perform auto-tabify after operation if TABIFY is non-nil.
;; Mark is kept if keep-clear is 'keep and cleared if keep-clear is 'clear.
- (let* ((start (cua--rectangle-top))
+ (let* ((inhibit-field-text-motion t)
+ (start (cua--rectangle-top))
(end (cua--rectangle-bot))
(l (cua--rectangle-left))
(r (1+ (cua--rectangle-right)))