From b5ba7095feb6d2c5e90e2ead540b8328caf8acc5 Mon Sep 17 00:00:00 2001
From: Ihor Radchenko <yantar92@posteo.net>
Date: Tue, 20 Feb 2024 12:43:51 +0300
Subject: * lisp/files.el (untrusted-content): New variable.

The new variable is to be used when buffer contents comes from untrusted
source.

(cherry picked from commit ccc188fcf98ad9166ee551fac9d94b2603c3a51b)
---
 lisp/files.el | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/lisp/files.el b/lisp/files.el
index 3e4ad7c0d44..762ba44c0cc 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -588,6 +588,14 @@ enable-dir-local-variables
 Some modes may wish to set this to nil to prevent directory-local
 settings being applied, but still respect file-local ones.")
 
+(defvar-local untrusted-content nil
+  "Non-nil means that current buffer originated from an untrusted source.
+Email clients and some other modes may set this non-nil to mark the
+buffer contents as untrusted.
+
+This variable might be subject to change without notice.")
+(put 'untrusted-content 'permanent-local t)
+
 ;; This is an odd variable IMO.
 ;; You might wonder why it is needed, when we could just do:
 ;; (set (make-local-variable 'enable-local-variables) nil)
