#undef isascii
#undef isspace
#undef isdigit
+#undef isxdigit
#undef isalpha
#undef isprint
#undef isalnum
#define isascii(x) (((x) & ~0x7f) == 0)
#define isspace(x) sane_istest(x,GIT_SPACE)
#define isdigit(x) sane_istest(x,GIT_DIGIT)
+#define isxdigit(x) \
+ (sane_istest(toupper(x), GIT_ALPHA | GIT_DIGIT) && toupper(x) < 'G')
#define isalpha(x) sane_istest(x,GIT_ALPHA)
#define isalnum(x) sane_istest(x,GIT_ALPHA | GIT_DIGIT)
#define isprint(x) sane_istest(x,GIT_PRINT)