From 5edcb9b308d84fdbb29b03e2940e3873fe28e4ed Mon Sep 17 00:00:00 2001
From: Gerhard Rieger <gerhard@dest-unreach.org>
Date: Fri, 8 Apr 2022 10:54:00 +0200
Subject: [PATCH] ctype(3) functions need there arguments to be unsigned char

---
 CHANGES       | 3 +++
 error.c       | 2 +-
 sysutils.c    | 6 +++---
 utils.c       | 2 +-
 vsnprintf_r.c | 2 +-
 xio-openssl.c | 2 +-
 xio-socket.c  | 2 +-
 7 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/CHANGES b/CHANGES
index 0dceb3f..98be1c5 100644
--- a/CHANGES
+++ b/CHANGES
@@ -37,6 +37,9 @@ Corrections:
 	or have trailing garbage.
 	Test: INTEGER_GARBAGE
 
+	ctype(3) functions need there arguments to be unsigned char.
+	Thanks to Taylor R Campbell for sending a patch.
+
 Porting:
 	OpenSSL, at least 1.1 on Ubuntu, crashed with SIGSEGV under certain
 	conditions: client connection to server with certificate with empty
diff --git a/error.c b/error.c
index f0ea73a..43ceebd 100644
--- a/error.c
+++ b/error.c
@@ -357,7 +357,7 @@ void msg2(
    syslp = bufp;
    *bufp++ = "DINWEF"[level];
 #if 0 /* only for debugging socat */
-   if (handler)  bufp[-1] = tolower(bufp[-1]); /* for debugging, low chars indicate messages from signal handlers */
+   if (handler)  bufp[-1] = tolower((unsigned char)bufp[-1]); /* for debugging, low chars indicate messages from signal handlers */
 #endif
    *bufp++ = ' ';
    strncpy(bufp, text, BUFLEN-(bufp-buff)-1);
diff --git a/sysutils.c b/sysutils.c
index 7f15128..32e4ba3 100644
--- a/sysutils.c
+++ b/sysutils.c
@@ -745,7 +745,7 @@ int xiosetenv(const char *varname, const char *value, int overwrite, const char
    progname = diag_get_string('p');
    envname[0] = '\0'; strncat(envname, progname, XIO_ENVNAMELEN-1);
    l = strlen(envname);
-   for (i = 0; i < l; ++i)  envname[i] = toupper(envname[i]);
+   for (i = 0; i < l; ++i)  envname[i] = toupper((unsigned char)envname[i]);
    strncat(envname+l, "_", XIO_ENVNAMELEN-l-1);
    l += 1;
    strncat(envname+l, varname, XIO_ENVNAMELEN-l-1);
@@ -771,7 +771,7 @@ int xiosetenv2(const char *varname, const char *varname2, const char *value,
    l += 1;
    strncat(envname+l, varname2, XIO_ENVNAMELEN-l-1);
    l += strlen(envname+l);
-   for (i = 0; i < l; ++i)  envname[i] = toupper(envname[i]);
+   for (i = 0; i < l; ++i)  envname[i] = toupper((unsigned char)envname[i]);
    return _xiosetenv(envname, value, overwrite, sep);
 #  undef XIO_ENVNAMELEN
 }
@@ -799,7 +799,7 @@ int xiosetenv3(const char *varname, const char *varname2, const char *varname3,
    l += 1;
    strncat(envname+l, varname3, XIO_ENVNAMELEN-l-1);
    l += strlen(envname+l);
-   for (i = 0; i < l; ++i)  envname[i] = toupper(envname[i]);
+   for (i = 0; i < l; ++i)  envname[i] = toupper((unsigned char)envname[i]);
    return _xiosetenv(envname, value, overwrite, sep);
 #  undef XIO_ENVNAMELEN
 }
diff --git a/utils.c b/utils.c
index 63f8a6b..5760831 100644
--- a/utils.c
+++ b/utils.c
@@ -97,7 +97,7 @@ static size_t sanitize_char(char c, char *o, int style) {
    int hn;	/* high nibble */
    int ln;	/* low nibble */
    int n;	/* written chars */
-   if (isprint(c)) {
+   if (isprint((unsigned char)c)) {
       *o = c;
       return 1;
    }
diff --git a/vsnprintf_r.c b/vsnprintf_r.c
index fe8a966..3b691c8 100644
--- a/vsnprintf_r.c
+++ b/vsnprintf_r.c
@@ -404,7 +404,7 @@ int vsnprintf_r(char *str, size_t size, const char *format, va_list ap) {
 	    do {
 	       fsize = 10*fsize+(c-'0');
 	       c = *format++;
-	    } while (c && isdigit(c));
+	    } while (c && isdigit((unsigned char)c));
 	    break;
 	 }
 	 if (c == '\0')  { break; }
diff --git a/xio-openssl.c b/xio-openssl.c
index 48fffa2..7d088cf 100644
--- a/xio-openssl.c
+++ b/xio-openssl.c
@@ -1507,7 +1507,7 @@ static int openssl_delete_cert_info(void) {
    progname = diag_get_string('p');
    envprefix[0] = '\0'; strncat(envprefix, progname, XIO_ENVNAMELEN-1);
    l = strlen(envprefix);
-   for (i = 0; i < l; ++i)  envprefix[i] = toupper(envprefix[i]);
+   for (i = 0; i < l; ++i)  envprefix[i] = toupper((unsigned char)envprefix[i]);
    strncat(envprefix+l, "_OPENSSL_", XIO_ENVNAMELEN-l-1);
 
 #if HAVE_VAR_ENVIRON
diff --git a/xio-socket.c b/xio-socket.c
index f02b3e2..465aaaf 100644
--- a/xio-socket.c
+++ b/xio-socket.c
@@ -1524,7 +1524,7 @@ int retropt_socket_pf(struct opt *opts, int *pf) {
    char *pfname;
 
    if (retropt_string(opts, OPT_PROTOCOL_FAMILY, &pfname) >= 0) {
-      if (isdigit(pfname[0])) {
+      if (isdigit((unsigned char)pfname[0])) {
 	 *pf = strtoul(pfname, NULL /*!*/, 0);
 #if WITH_IP4
       } else if (!strcasecmp("inet", pfname) ||