From e4996d8dce2e6d499efaa68e79a8be13cd9275bf Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Mon, 4 Aug 2014 21:25:19 +0100
Subject: [PATCH] don't set shrink too low

---
 libvips/resample/bicubic.cpp | 3 +++
 tools/vipsthumbnail.c        | 3 ++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/libvips/resample/bicubic.cpp b/libvips/resample/bicubic.cpp
index 1488f8c9..66bfa5b6 100644
--- a/libvips/resample/bicubic.cpp
+++ b/libvips/resample/bicubic.cpp
@@ -353,6 +353,7 @@ vips_interpolate_bicubic_interpolate( VipsInterpolate *interpolate,
 		bicubic_int_tab<unsigned char, 0, UCHAR_MAX>(
 			out, p, bands, lskip,
 			cxi, cyi );
+
 	/*
 
 	   Handy for benchmarking
@@ -360,11 +361,13 @@ vips_interpolate_bicubic_interpolate( VipsInterpolate *interpolate,
 		bicubic_float_tab<unsigned char>(
 			out, p, bands, lskip,
 			cxf, cyf );
+
 		bicubic_notab<unsigned char>(
 			out, p, bands, lskip,
 			x - ix, y - iy );
 
 	 */
+
 		break;
 
 	case VIPS_FORMAT_CHAR:
diff --git a/tools/vipsthumbnail.c b/tools/vipsthumbnail.c
index 14d3e908..75d4ee58 100644
--- a/tools/vipsthumbnail.c
+++ b/tools/vipsthumbnail.c
@@ -229,7 +229,8 @@ calculate_shrink( VipsImage *im, double *residual,
 	 *
 	 * We want to shrink by less for interpolators with larger windows.
 	 */
-	int shrink = floor( factor2 ) / VIPS_MAX( window_size / 2, 1 );
+	int shrink = VIPS_MAX( 1, 
+		floor( factor2 ) / VIPS_MAX( 1, window_size / 2 ) );
 
 	if( residual &&
 		direction == VIPS_DIRECTION_HORIZONTAL ) {