fix crash when window is resized smallerHEADmaster

If the cursor was being displayed and its previous position is now outside
the resized window, we could crash when trying to erase the old cursor.

1 files changed, 6 insertions, 3 deletions

diff --git a/xlib.c b/xlib.c
index a94e8f8..33e819a 100644
--- a/xlib.c
+++ b/xlib.c
@@ -401,14 +401,17 @@ static void blit_slice(struct uudisp *d, int idx, int x1, int x2)
 void uudisp_refresh(struct uudisp *d, struct uuterm *t)
 {
 	struct priv *p = (void *)&d->priv;
+	int w = t->w < d->w ? t->w : d->w;
 	int h = t->h < d->h ? t->h : d->h;
 	int x1, x2, idx, y;
 
 	/* Clean up cursor first.. */
 	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);
+		if (p->curs_x < w && p->curs_y < h) {
+			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);
+		}
 		p->curs_on = 0;
 	}