Make sure to use unsigned char for is*() functions

On some platforms, the implementation is such that a signed char
triggers a warning when used with is*() functions.  On others, the
behavior is outright buggy when presented with a char that happens
to get promoted to a negative integer.

The safest thing is to cast the char that's used to an unsigned char.

Reviewed-by: Andy Polyakov <appro@openssl.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/apps/ca.c b/apps/ca.c
index 9a1b69f68d..716df02fac 100644
--- a/apps/ca.c
+++ b/apps/ca.c
@@ -731,7 +731,7 @@ end_of_options:
             goto end;
         }
         for ( ; *p; p++) {
-            if (!isxdigit(*p)) {
+            if (!isxdigit(_UC(*p))) {
                 BIO_printf(bio_err,
                            "entry %d: bad char 0%o '%c' in serial number\n",
                            i + 1, *p, *p);