Eliminate use of uninitialized value in GetFillAlpha()

Credit OSS Fuzz

diff --git a/MagickCore/draw.c b/MagickCore/draw.c
index 68dbb747af1ed5479123c48dfbc3bf0be62c2cbb..ad2c28104a710b83bd7fe5e918687dcce76ea734 100644 (file)
--- a/MagickCore/draw.c
+++ b/MagickCore/draw.c
@@ -3941,7 +3941,7 @@ static double GetFillAlpha(PolygonInfo *polygon_info,const double mid,
         continue;
       }
     i=(ssize_t) MagickMax((double) p->highwater,1.0);
-    for ( ; i < (ssize_t) p->number_points; i++)
+    for ( ; i < (ssize_t) (p->number_points-1); i++)
       if ((double) y <= p->points[i].y)
         break;
     q=p->points+i-1;