signed vs unsigned char in coding.h

[Dan Nicolaescu]

struct coding_system in coding.h contains this:

      char *safe_charsets;


and coding.c has this:

#define SAFE_CHARSET_P(coding, id)      \
  ((id) <= (coding)->max_charset_id     \
   && (coding)->safe_charsets[id] >= 0)

on some platforms "char" is unsigned by default, so the above >=0
comparison is always true.

What is the intention here, should safe_charsets be defined as "signed char" ?