kc3-lang/md4c

diff --git a/md4c/md4c.c b/md4c/md4c.c
index d97a2e6..1303d15 100644
--- a/md4c/md4c.c
+++ b/md4c/md4c.c
@@ -202,17 +202,17 @@ md_log(MD_CTX* ctx, const char* fmt, ...)
 
 /* Character classification.
  * Note we assume ASCII compatibility of code points < 128 here. */
-#define ISASCII_(ch)            ((ch) <= 127)
-#define ISBLANK_(ch)            ((ch) == _T(' ') || (ch) == _T('\t'))
-#define ISNEWLINE_(ch)          ((ch) == _T('\r') || (ch) == _T('\n'))
+#define ISASCII_(ch)            ((unsigned)(ch) <= 127)
+#define ISBLANK_(ch)            ((unsigned)(ch) == _T(' ') || (unsigned)(ch) == _T('\t'))
+#define ISNEWLINE_(ch)          ((unsigned)(ch) == _T('\r') || (unsigned)(ch) == _T('\n'))
 #define ISWHITESPACE_(ch)       (ISBLANK_(ch) || ch == _T('\v') || ch == _T('\f'))
-#define ISCNTRL_(ch)            ((ch) <= 31 || (ch) == 127)
-#define ISPUNCT_(ch)            ((33 <= (ch) && (ch) <= 47) || (58 <= (ch) && (ch) <= 64) || (91 <= (ch) && (ch) <= 96) || (123 <= (ch) && (ch) <= 126))
-#define ISUPPER_(ch)            (_T('A') <= (ch) && (ch) <= _T('Z'))
-#define ISLOWER_(ch)            (_T('a') <= (ch) && (ch) <= _T('z'))
+#define ISCNTRL_(ch)            ((unsigned)(ch) <= 31 || (unsigned)(ch) == 127)
+#define ISPUNCT_(ch)            ((33 <= (unsigned)(ch) && (unsigned)(ch) <= 47) || (58 <= (unsigned)(ch) && (unsigned)(ch) <= 64) || (91 <= (unsigned)(ch) && (unsigned)(ch) <= 96) || (123 <= (unsigned)(ch) && (unsigned)(ch) <= 126))
+#define ISUPPER_(ch)            (_T('A') <= (unsigned)(ch) && (unsigned)(ch) <= _T('Z'))
+#define ISLOWER_(ch)            (_T('a') <= (unsigned)(ch) && (unsigned)(ch) <= _T('z'))
 #define ISALPHA_(ch)            (ISUPPER_(ch) || ISLOWER_(ch))
-#define ISDIGIT_(ch)            (_T('0') <= (ch) && (ch) <= _T('9'))
-#define ISXDIGIT_(ch)           (ISDIGIT_(ch) || (_T('a') <= (ch) && (ch) <= _T('f')) || (_T('A') <= (ch) && (ch) <= _T('F')))
+#define ISDIGIT_(ch)            (_T('0') <= (unsigned)(ch) && (unsigned)(ch) <= _T('9'))
+#define ISXDIGIT_(ch)           (ISDIGIT_(ch) || (_T('a') <= (unsigned)(ch) && (unsigned)(ch) <= _T('f')) || (_T('A') <= (unsigned)(ch) && (unsigned)(ch) <= _T('F')))
 #define ISALNUM_(ch)            (ISALPHA_(ch) || ISDIGIT_(ch))
 #define ISANYOF_(ch, palette)   (md_strchr((palette), (ch)) != NULL)