Fix a memory error.

Author: walknight

libretro.c

@@ -921,9 +921,11 @@ void osint_render(void)
 
  /* Is this vector a point? */
  if (vectors_draw[i].x0 == vectors_draw[i].x1 && vectors_draw[i].y0 == vectors_draw[i].y1
- /* That isn't joining two lines. */
- && (vectors_draw[i].x0 != vectors_draw[i-1].x1 || vectors_draw[i].x1 != vectors_draw[i+1].x0 ||
- vectors_draw[i].y0 != vectors_draw[i-1].y1 || vectors_draw[i].y1 != vectors_draw[i+1].y0))
+ /* That isn't joining two lines. */
+ && (i == 0 ||
+ vectors_draw[i].x0 != vectors_draw[i - 1].x1 || vectors_draw[i].y0 != vectors_draw[i - 1].y1 ||
+ i == vector_draw_cnt - 1 ||
+ vectors_draw[i].x1 != vectors_draw[i + 1].x0 || vectors_draw[i].y1 != vectors_draw[i + 1].y0))
 #if 0
  if (vectors_draw[i].p0 == vectors_draw[i].p1
  && (vectors_draw[i].p0 != vectors_draw[i-1].p1 || vectors_draw[i].p1 != vectors_draw[i+1].p0))