Remove the compilation-arrow-overlay on a major mode change/reinitialization

At the same time, remove the 2-character left margin.

* lisp/progmodes/compile.el (compilation-set-up-arrow-spec-in-margin): put
compilation-tear-down-arrow-spec-in-margin onto change-major-mode-hook.

1 files changed, 4 insertions, 1 deletions

diff --git a/lisp/progmodes/compile.el b/lisp/progmodes/compile.el
index f0b34c702ca..d80fef3103e 100644
--- a/lisp/progmodes/compile.el
+++ b/lisp/progmodes/compile.el
@@ -2625,7 +2625,10 @@ Actual value is never used, only the text property.")
         (make-overlay overlay-arrow-position overlay-arrow-position))
   (overlay-put compilation-arrow-overlay
                'before-string compilation--dummy-string)
-  (set-window-margins (selected-window) (+ (or (car (window-margins)) 0) 2)))
+  (set-window-margins (selected-window) (+ (or (car (window-margins)) 0) 2))
+  ;; Take precautions against `compilation-mode' getting reinitialized.
+  (add-hook 'change-major-mode-hook
+            'compilation-tear-down-arrow-spec-in-margin nil t))
 
 (defun compilation-tear-down-arrow-spec-in-margin ()
   "Restore compilation-arrow-overlay to not using the margin, which is removed."