argp: Don't pass invalid arguments to isspace, isalnum, isalpha, isdigit.

* lib/argp-help.c (SKIPWS): Cast character to 'unsigned char' before passing it
to isspace().
(fill_in_uparams): Likewise for isalpha(), isalnum(), isdigit().
(canon_doc_option): Likewise for isspace(), isalnum().

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

diff --git a/argp/argp-help.c b/argp/argp-help.c
index 5844d5b..d686a23 100644 (file)
--- a/argp/argp-help.c
+++ b/argp/argp-help.c
@@ -166,7 +166,7 @@ fill_in_uparams (const struct argp_state *state)
 {
   const char *var = getenv ("ARGP_HELP_FMT");
 
-#define SKIPWS(p) do { while (isspace (*p)) p++; } while (0);
+#define SKIPWS(p) do { while (isspace ((unsigned char) *p)) p++; } while (0);
 
   if (var)
     /* Parse var. */
@@ -174,14 +174,14 @@ fill_in_uparams (const struct argp_state *state)
       {
        SKIPWS (var);
 
-       if (isalpha (*var))
+       if (isalpha ((unsigned char) *var))
          {
            size_t var_len;
            const struct uparam_name *un;
            int unspec = 0, val = 0;
            const char *arg = var;
 
-           while (isalnum (*arg) || *arg == '-' || *arg == '_')
+           while (isalnum ((unsigned char) *arg) || *arg == '-' || *arg == '_')
              arg++;
            var_len = arg - var;
 
@@ -206,10 +206,10 @@ fill_in_uparams (const struct argp_state *state)
                else
                  val = 1;
              }
-           else if (isdigit (*arg))
+           else if (isdigit ((unsigned char) *arg))
              {
                val = atoi (arg);
-               while (isdigit (*arg))
+               while (isdigit ((unsigned char) *arg))
                  arg++;
                SKIPWS (arg);
              }
@@ -713,12 +713,12 @@ canon_doc_option (const char **name)
 {
   int non_opt;
   /* Skip initial whitespace.  */
-  while (isspace (**name))
+  while (isspace ((unsigned char) **name))
     (*name)++;
   /* Decide whether this looks like an option (leading `-') or not.  */
   non_opt = (**name != '-');
   /* Skip until part of name used for sorting.  */
-  while (**name && !isalnum (**name))
+  while (**name && !isalnum ((unsigned char) **name))
     (*name)++;
   return non_opt;
 }