Subject: bug#25599: Why edit markers after insert?

From: nitish chandra <[email-masked]>
Date: Wed, 8 Mar 2017 21:44:59 +0530

In primitive-undo in simple.el, aroud line 2550 (in master) we adjust the
markers after the insertion.

(dolist (adj valid-marker-adjustments)
               (set-marker (car adj)
                           (- (car adj) (cdr adj))))

Why is this needed? Won't insert take care of adjusting the markers?