From 7189c6df83da4c6c93f7bd4ec367a2f9ae040699 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Mattias=20Engdeg=C3=A5rd?= <mattiase@acm.org>
Date: Sat, 5 Jul 2025 13:09:43 +0200
Subject: [PATCH] Read characters from functions as multibyte

Previously, latin-1 was incorrectly assumed (bug#70988).

* src/lread.c (readchar): Set multibyte flag.
* test/src/lread-tests.el (lread-function-source): New test.

(cherry picked from commit 553a6c407f28c4faa832c8cda462267ef75bff38)
---
 src/lread.c             | 3 +++
 test/src/lread-tests.el | 5 +++++
 2 files changed, 8 insertions(+)

diff --git a/src/lread.c b/src/lread.c
index 40eb6ad7875..6cd6735a215 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -396,6 +396,9 @@ readchar (Lisp_Object readcharfun, bool *multibyte)
       goto read_multibyte;
     }
 
+  if (multibyte)
+    *multibyte = 1;
+
   tem = call0 (readcharfun);
 
   if (!FIXNUMP (tem))
diff --git a/test/src/lread-tests.el b/test/src/lread-tests.el
index 40640e79eed..d832cc9aa4e 100644
--- a/test/src/lread-tests.el
+++ b/test/src/lread-tests.el
@@ -387,4 +387,9 @@ literals (Bug#20852)."
     (goto-char (point-min))
     (should-error (read (current-buffer)) :type 'end-of-file)))
 
+(ert-deftest lread-function-source ()
+  (let* ((s '(#x41 #x222a #xff -1))
+         (val (read (lambda () (pop s)))))
+    (should (equal (symbol-name val) "A∪ÿ"))))
+
 ;;; lread-tests.el ends here
-- 
2.39.5