>From 71958eb7080485d7291b8b622b09e6b198f0d920 Mon Sep 17 00:00:00 2001
From: Bruno Haible <bruno@clisp.org>
Date: Fri, 2 Apr 2021 19:47:53 +0200
Subject: [PATCH 1/7] strto*l: Don't pass invalid arguments to isspace,
 isalnum, toupper.

* lib/strtol.c (ISSPACE, ISALPHA, TOUPPER): Cast argument to
'unsigned char' before passing it to the functions isspace(), isalpha(),
toupper().
---
 ChangeLog    |  7 +++++++
 lib/strtol.c | 12 ++++++------
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index f4e766f..0bf4c58 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2021-04-02  Bruno Haible  <bruno@clisp.org>
 
+	strto*l: Don't pass invalid arguments to isspace, isalnum, toupper.
+	* lib/strtol.c (ISSPACE, ISALPHA, TOUPPER): Cast argument to
+	'unsigned char' before passing it to the functions isspace(), isalpha(),
+	toupper().
+
+2021-04-02  Bruno Haible  <bruno@clisp.org>
+
 	glob: Reject ~user syntax, when flag GLOB_TILDE_CHECK is given.
 	Reported and patch suggested by Eli Zaretskii <eliz@gnu.org> in
 	<https://lists.gnu.org/archive/html/bug-gnulib/2021-03/msg00136.html>.
diff --git a/lib/strtol.c b/lib/strtol.c
index 2f2159b..14836d0 100644
--- a/lib/strtol.c
+++ b/lib/strtol.c
@@ -166,13 +166,13 @@
 # define UCHAR_TYPE unsigned char
 # define STRING_TYPE char
 # ifdef USE_IN_EXTENDED_LOCALE_MODEL
-#  define ISSPACE(Ch) __isspace_l ((Ch), loc)
-#  define ISALPHA(Ch) __isalpha_l ((Ch), loc)
-#  define TOUPPER(Ch) __toupper_l ((Ch), loc)
+#  define ISSPACE(Ch) __isspace_l ((unsigned char) (Ch), loc)
+#  define ISALPHA(Ch) __isalpha_l ((unsigned char) (Ch), loc)
+#  define TOUPPER(Ch) __toupper_l ((unsigned char) (Ch), loc)
 # else
-#  define ISSPACE(Ch) isspace (Ch)
-#  define ISALPHA(Ch) isalpha (Ch)
-#  define TOUPPER(Ch) toupper (Ch)
+#  define ISSPACE(Ch) isspace ((unsigned char) (Ch))
+#  define ISALPHA(Ch) isalpha ((unsigned char) (Ch))
+#  define TOUPPER(Ch) toupper ((unsigned char) (Ch))
 # endif
 #endif
 
-- 
2.7.4