Add some unsigned char casts for tolower() usage

2 files changed, 4 insertions, 4 deletions

diff --git a/tbl_layout.c b/tbl_layout.c
index 50e9728d..cc4fdfb5 100644
--- a/tbl_layout.c
+++ b/tbl_layout.c
@@ -130,7 +130,7 @@ mod:
 
 	/* TODO: GNU has many more extensions. */
 
-	switch (tolower(p[(*pos)++])) {
+	switch (tolower((unsigned char)p[(*pos)++])) {
 	case ('z'):
 		cp->flags |= TBL_CELL_WIGN;
 		goto mod;
@@ -160,7 +160,7 @@ mod:
 		return(0);
 	}
 
-	switch (tolower(p[(*pos)++])) {
+	switch (tolower((unsigned char)p[(*pos)++])) {
 	case ('b'):
 		cp->flags |= TBL_CELL_BOLD;
 		goto mod;
@@ -185,7 +185,7 @@ cell(struct tbl_node *tbl, struct tbl_row *rp,
 	/* Parse the column position (`r', `R', `|', ...). */
 
 	for (i = 0; i < KEYS_MAX; i++)
-		if (tolower(p[*pos]) == keys[i].name)
+		if (tolower((unsigned char)p[*pos]) == keys[i].name)
 			break;
 
 	if (KEYS_MAX == i) {
diff --git a/tbl_opts.c b/tbl_opts.c
index 227deb1f..28b658f7 100644
--- a/tbl_opts.c
+++ b/tbl_opts.c
@@ -188,7 +188,7 @@ again:	/*
 	/* Copy up to first non-alpha character. */
 
 	for (sv = *pos, i = 0; i < KEY_MAXNAME; i++, (*pos)++) {
-		buf[i] = tolower(p[*pos]);
+		buf[i] = tolower((unsigned char)p[*pos]);
 		if ( ! isalpha((unsigned char)buf[i]))
 			break;
 	}