From: Alan Mackenzie <acm@muc.de>
Date: Sun, 29 Sep 2019 15:39:16 +0000 (+0000)
Subject: Remove the compilation-arrow-overlay on a major mode change/reinitialization
X-Git-Tag: emacs-27.0.90~1371
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=53b71fd4adf6de6b4d8b37e8ab3d56eb93e7ce92;p=emacs.git

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.
---

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."