use xor instead of incrementing blink

Because blink is a signed integer, an eventual overflow would result in
undefined behavior.

3 files changed, 3 insertions, 3 deletions

diff --git a/dblbuf.c b/dblbuf.c
index f6cbd88..afa180c 100644
--- a/dblbuf.c
+++ b/dblbuf.c
@@ -176,7 +176,7 @@ void uudisp_refresh(struct uudisp *d, struct uuterm *t)
 		blit_slice(d, idx, x1, x2);
 	}
 
-	if (d->blink & 1) {
+	if (d->blink) {
 		unsigned long rev = expand_color(d, 15);
 		int idx = t->rows[t->y]->idx;
 		b->slices[idx].colors[2*t->x] ^= rev;
diff --git a/main.c b/main.c
index 784f7f2..422d707 100644
--- a/main.c
+++ b/main.c
@@ -66,7 +66,7 @@ int main(int argc, char *argv[])
 		tv.tv_sec = 0;
 		tv.tv_usec = 250000;
 		if (select(max, &fds, &wfds, NULL, &tv) <= 0) {
-			d.blink++;
+			d.blink ^= 1;
 			FD_ZERO(&fds);
 		}
 
diff --git a/xlib.c b/xlib.c
index d5c078c..a94e8f8 100644
--- a/xlib.c
+++ b/xlib.c
@@ -405,7 +405,7 @@ void uudisp_refresh(struct uudisp *d, struct uuterm *t)
 	int x1, x2, idx, y;
 
 	/* Clean up cursor first.. */
-	if (p->curs_on && (!(d->blink&1) || t->x != p->curs_x || t->y != p->curs_y)) {
+	if (p->curs_on && (!d->blink || t->x != p->curs_x || t->y != p->curs_y)) {
 		idx = t->rows[p->curs_y]->idx;
 		if ((unsigned)p->slices_y[idx] < d->h)
 			blit_slice(d, idx, p->curs_x, p->curs_x);