tweaks: rename a function, to be simpler and more accurate

src/chars.c

@@ -638,7 +638,7 @@ char *mbrevstrpbrk(const char *head, const char *accept, const char *pointer)
 #if defined(ENABLE_NANORC) && (!defined(NANO_TINY) || defined(ENABLE_JUSTIFY))
 /* Return TRUE if the given string contains at least one blank character,
  * and FALSE otherwise. */
-bool has_blank_mbchars(const char *s)
+bool has_blank_char(const char *s)
 {
 #ifdef ENABLE_UTF8
 	if (use_utf8) {

src/proto.h

@@ -228,7 +228,7 @@ char *revstrpbrk(const char *head, const char *accept, const char *index);
 char *mbrevstrpbrk(const char *head, const char *accept, const char *index);
 #endif
 #if defined(ENABLE_NANORC) && (!defined(NANO_TINY) || defined(ENABLE_JUSTIFY))
-bool has_blank_mbchars(const char *s);
+bool has_blank_char(const char *s);
 #endif
 #ifdef ENABLE_UTF8
 bool is_valid_unicode(wchar_t wc);

src/rcfile.c

@@ -1129,7 +1129,7 @@ void parse_rcfile(FILE *rcstream, bool syntax_only)
 		}
 		if (strcasecmp(rcopts[i].name, "matchbrackets") == 0) {
 			matchbrackets = option;
-			if (has_blank_mbchars(matchbrackets)) {
+			if (has_blank_char(matchbrackets)) {
 				rcfile_error(N_("Non-blank characters required"));
 				free(matchbrackets);
 				matchbrackets = NULL;
@@ -1149,13 +1149,13 @@ void parse_rcfile(FILE *rcstream, bool syntax_only)
 #endif
 #ifdef ENABLE_JUSTIFY
 		if (strcasecmp(rcopts[i].name, "punct") == 0) {
-			if (has_blank_mbchars(option)) {
+			if (has_blank_char(option)) {
 				rcfile_error(N_("Non-blank characters required"));
 				free(option);
 			} else
 				punct = option;
 		} else if (strcasecmp(rcopts[i].name, "brackets") == 0) {
-			if (has_blank_mbchars(option)) {
+			if (has_blank_char(option)) {
 				rcfile_error(N_("Non-blank characters required"));
 				free(option);
 			} else