From 65a259a0258b2036b168cdeff6e9db434471225a Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Wed, 20 Feb 2019 15:15:50 +0000
Subject: [PATCH] prevent /0 in freq mask for very small masks

see https://github.com/libvips/libvips/issues/1236
---
 libvips/create/mask.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/libvips/create/mask.c b/libvips/create/mask.c
index 5d3739b6..66f8a197 100644
--- a/libvips/create/mask.c
+++ b/libvips/create/mask.c
@@ -58,8 +58,11 @@ vips_mask_point( VipsPoint *point, int x, int y )
 {
 	VipsMask *mask = VIPS_MASK( point ); 
 	VipsMaskClass *class = VIPS_MASK_GET_CLASS( point ); 
-	int half_width = point->width / 2;
-	int half_height = point->height / 2;
+
+	/* VIPS_MAX to prevent /0.
+	 */
+	int half_width = VIPS_MAX( point->width / 2, 1 );
+	int half_height = VIPS_MAX( point->height / 2, 1 );
 
 	double result;