From 6fea2e7c57f00ff3a6436505e02c194c53a6c314 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Fri, 13 Dec 2019 12:45:49 +0000
Subject: [PATCH 1/2] clip negatives off LABS L in tiff save

Negative L in LABS needs to be trimmed off before savingf as TIFF.
Thanks angelmixu.

See https://github.com/libvips/libvips/issues/1499
---
 libvips/foreign/vips2tiff.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/libvips/foreign/vips2tiff.c b/libvips/foreign/vips2tiff.c
index e548f143..3e338eec 100644
--- a/libvips/foreign/vips2tiff.c
+++ b/libvips/foreign/vips2tiff.c
@@ -1235,23 +1235,25 @@ invert_band0( Wtiff *wtiff, VipsPel *q, VipsPel *p, int n )
 static void
 LabS2Lab16( VipsPel *q, VipsPel *p, int n, int samples_per_pixel )
 {
-	int x;
 	short *p1 = (short *) p;
 	unsigned short *q1 = (unsigned short *) q;
 
+	int x;
+
         for( x = 0; x < n; x++ ) {
+		int v;
 		int i;
 
-                /* TIFF uses unsigned 16 bit ... move zero, scale up L.
+                /* LABS L can be negative.
                  */
-                q1[0] = VIPS_LSHIFT_INT( (int) p1[0], 1 );
+                q1[0] = VIPS_LSHIFT_INT( VIPS_MAX( 0, p1[0] ), 1 );
 
 		for( i = 1; i < samples_per_pixel; i++ )
 			q1[i] = p1[i];
 
 		q1 += samples_per_pixel;
 		p1 += samples_per_pixel;
-    }
+	}
 }
 
 /* Pack the pixels in @area from @in into a TIFF tile buffer.

From 112dc9101a49eea12afd4dc6cec3aaa2ccb58f1b Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Fri, 13 Dec 2019 14:19:09 +0000
Subject: [PATCH 2/2] remove early shutdown from tiff reader

since streams do this automatically now
---
 libvips/conversion/sequential.c | 2 +-
 libvips/foreign/tiff2vips.c     | 9 ---------
 libvips/foreign/vips2tiff.c     | 1 -
 3 files changed, 1 insertion(+), 11 deletions(-)

diff --git a/libvips/conversion/sequential.c b/libvips/conversion/sequential.c
index c90b4cdc..1823ba48 100644
--- a/libvips/conversion/sequential.c
+++ b/libvips/conversion/sequential.c
@@ -195,7 +195,7 @@ vips_sequential_build( VipsObject *object )
 	if( vips_linecache( sequential->in, &t, 
 		"tile_height", sequential->tile_height,
 		"access", VIPS_ACCESS_SEQUENTIAL,
-		/* We need seq caches to persist across minimise, in case
+		/* We need seq caches to persist across minimise in case
 		 * someone is trying to read an image with a series of crop
 		 * operations.
 		 */
diff --git a/libvips/foreign/tiff2vips.c b/libvips/foreign/tiff2vips.c
index 933325e4..1023a132 100644
--- a/libvips/foreign/tiff2vips.c
+++ b/libvips/foreign/tiff2vips.c
@@ -2041,15 +2041,6 @@ rtiff_stripwise_generate( VipsRegion *or,
 		rtiff->y_pos += hit.height;
 	}
 
-	/* Shut down the input file as soon as we can.
-	 */
-	if( rtiff->y_pos >= or->im->Ysize ) {
-#ifdef DEBUG
-		printf( "rtiff_stripwise_generate: early shutdown\n" );
-#endif /*DEBUG*/
-		rtiff_free( rtiff );
-	}
-
 	VIPS_GATE_STOP( "rtiff_stripwise_generate: work" ); 
 
 	return( 0 );
diff --git a/libvips/foreign/vips2tiff.c b/libvips/foreign/vips2tiff.c
index 3e338eec..8fcda841 100644
--- a/libvips/foreign/vips2tiff.c
+++ b/libvips/foreign/vips2tiff.c
@@ -1241,7 +1241,6 @@ LabS2Lab16( VipsPel *q, VipsPel *p, int n, int samples_per_pixel )
 	int x;
 
         for( x = 0; x < n; x++ ) {
-		int v;
 		int i;
 
                 /* LABS L can be negative.