this should 'fix' them all, except for the various parse.y.  A grep in
usr.sbin shows that noone casts there.  (these calls are present in
the parse.y files and not added by yacc.)

the ones in diff are maybe a bit redundant, except for one or two case
all should already pass uint8_t and/or unsigned char, changing just in
case in the future the types will change.

(if ok i'll commit the diff bits separately to diff.git and then sync
as usual.)

diff /home/op/w/gotd
commit - c2a4f618fa3c9683fbb5f384b117f7e45a041122
path + /home/op/w/gotd
blob - 238ecb9d0ee975efd8eacc55de14b8cfb69792de
file + lib/diff_atomize_text.c
--- lib/diff_atomize_text.c
+++ lib/diff_atomize_text.c
@@ -69,7 +69,7 @@ diff_data_atomize_text_lines_fd(struct diff_data *d)
 			while (eol == 0 && i < r) {
 				if (buf[i] != '\r' && buf[i] != '\n') {
 					if (!ignore_whitespace
-					    || !isspace(buf[i]))
+					    || !isspace((unsigned char)buf[i]))
 						hash = diff_atom_hash_update(
 						    hash, buf[i]);
 					if (buf[i] == '\0')
@@ -142,7 +142,7 @@ diff_data_atomize_text_lines_mmap(struct diff_data *d)
 
 		while (line_end < end && *line_end != '\r' && *line_end != '\n') {
 			if (!ignore_whitespace
-			    || !isspace(*line_end))
+			    || !isspace((unsigned char)*line_end))
 				hash = diff_atom_hash_update(hash, *line_end);
 			if (*line_end == '\0')
 				embedded_nul = true;
blob - 26fa788bccf6fc4e54a3c2efe5e6a389a1d34032
file + lib/diff_main.c
--- lib/diff_main.c
+++ lib/diff_main.c
@@ -62,11 +62,11 @@ buf_cmp(const unsigned char *left, size_t left_len,
 			unsigned char cl = left[il];
 			unsigned char cr = right[ir];
 
-			if (isspace(cl) && il < left_len) {
+			if (isspace((unsigned char)cl) && il < left_len) {
 				il++;
 				continue;
 			}
-			if (isspace(cr) && ir < right_len) {
+			if (isspace((unsigned char)cr) && ir < right_len) {
 				ir++;
 				continue;
 			}
@@ -80,12 +80,12 @@ buf_cmp(const unsigned char *left, size_t left_len,
 		}
 		while (il < left_len) {
 			unsigned char cl = left[il++];
-			if (!isspace(cl))
+			if (!isspace((unsigned char)cl))
 				return 1;
 		}
 		while (ir < right_len) {
 			unsigned char cr = right[ir++];
-			if (!isspace(cr))
+			if (!isspace((unsigned char)cr))
 				return -1;
 		}
 
blob - a487dffb531fb051aa859f3c1ac13816fdfcd926
file + lib/gitproto.c
--- lib/gitproto.c
+++ lib/gitproto.c
@@ -54,13 +54,13 @@ tokenize_line(char **tokens, char *line, int len, int 
 		tokens[i] = NULL;
 
 	for (i = 0; n < len && i < maxtokens; i++) {
-		while (isspace(*line)) {
+		while (isspace((unsigned char)*line)) {
 			line++;
 			n++;
 		}
 		p = line;
 		while (*line != '\0' && n < len &&
-		    (!isspace(*line) || i == maxtokens - 1)) {
+		    (!isspace((unsigned char)*line) || i == maxtokens - 1)) {
 			line++;
 			n++;
 		}
blob - 114e0ca8c6f110af5f8ebfd87ac1cdd552fbc92c
file + lib/object_parse.c
--- lib/object_parse.c
+++ lib/object_parse.c
@@ -410,12 +410,14 @@ parse_gmtoff(time_t *gmtoff, const char *tzstr)
 	else if (*p != '+')
 		return got_error(GOT_ERR_BAD_OBJ_DATA);
 	p++;
-	if (!isdigit(*p) && !isdigit(*(p + 1)))
+	if (!isdigit((unsigned char)*p) &&
+	    !isdigit((unsigned char)*(p + 1)))
 		return got_error(GOT_ERR_BAD_OBJ_DATA);
 	h = (((*p - '0') * 10) + (*(p + 1) - '0'));
 
 	p += 2;
-	if (!isdigit(*p) && !isdigit(*(p + 1)))
+	if (!isdigit((unsigned char)*p) &&
+	    !isdigit((unsigned char)*(p + 1)))
 		return got_error(GOT_ERR_BAD_OBJ_DATA);
 	m = ((*p - '0') * 10) + (*(p + 1) - '0');
 
blob - 52cedcef2588aa0c074d4d486c05e33a3bac7eb4
file + lib/pkt.c
--- lib/pkt.c
+++ lib/pkt.c
@@ -144,7 +144,7 @@ got_pkt_readpkt(int *outlen, int fd, char *buf, int bu
 	if (chattygot > 1) {
 		fprintf(stderr, "%s: readpkt: %zd:\t", getprogname(), n);
 		for (i = 0; i < n; i++) {
-			if (isprint(buf[i]))
+			if (isprint((unsigned char)buf[i]))
 				fputc(buf[i], stderr);
 			else
 				fprintf(stderr, "[0x%.2x]", buf[i]);
@@ -179,7 +179,7 @@ got_pkt_writepkt(int fd, char *buf, int nbuf, int chat
 	if (chattygot > 1) {
 		fprintf(stderr, "%s: writepkt: %s:\t", getprogname(), len);
 		for (i = 0; i < nbuf; i++) {
-			if (isprint(buf[i]))
+			if (isprint((unsigned char)buf[i]))
 				fputc(buf[i], stderr);
 			else
 				fprintf(stderr, "[0x%.2x]", buf[i]);
blob - 4fa55782d6cfa72a92ffedfb310e3ac0e508e55c
file + libexec/got-fetch-pack/got-fetch-pack.c
--- libexec/got-fetch-pack/got-fetch-pack.c
+++ libexec/got-fetch-pack/got-fetch-pack.c
@@ -208,7 +208,7 @@ fetch_error(const char *buf, size_t len)
 	size_t i;
 
 	for (i = 0; i < len && i < sizeof(msg) - 1; i++) {
-		if (!isprint(buf[i]))
+		if (!isprint((unsigned char)buf[i]))
 			return got_error_msg(GOT_ERR_BAD_PACKET,
 			    "non-printable error message received from server");
 		msg[i] = buf[i];
blob - 7069d8b17d0928e260d85033e81ff7ac104c27dd
file + libexec/got-send-pack/got-send-pack.c
--- libexec/got-send-pack/got-send-pack.c
+++ libexec/got-send-pack/got-send-pack.c
@@ -181,7 +181,7 @@ send_error(const char *buf, size_t len)
 	size_t i;
 
 	for (i = 0; i < len && i < sizeof(msg) - 1; i++) {
-		if (!isprint(buf[i]))
+		if (!isprint((unsigned char)buf[i]))
 			return got_error_msg(GOT_ERR_BAD_PACKET,
 			    "non-printable error message received from server");
 		msg[i] = buf[i];