From 73c133143970625e5dbacba201fefe154c68e538 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Wed, 11 Mar 2020 09:08:39 +0000
Subject: [PATCH] swap abs() for fabs() in composite

The non-vector fallback path had abs(double). Thanks brcarp.

See https://github.com/libvips/libvips/issues/1572
---
 libvips/conversion/composite.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libvips/conversion/composite.cpp b/libvips/conversion/composite.cpp
index 84ad9cfb..ad44a93b 100644
--- a/libvips/conversion/composite.cpp
+++ b/libvips/conversion/composite.cpp
@@ -621,7 +621,7 @@ vips_composite_base_blend( VipsCompositeBase *composite,
 
 		case VIPS_BLEND_MODE_DIFFERENCE:
 			for( int b = 0; b < bands; b++ ) 
-				f[b] = abs( B[b] - A[b] );
+				f[b] = fabs( B[b] - A[b] );
 			break;
 
 		case VIPS_BLEND_MODE_EXCLUSION: