diff --git a/ChangeLog b/ChangeLog
index dbbb6984..7c2e8aa9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -4,6 +4,17 @@
 - add max and min to region shrink [rgluskin]
 - allow \ as an escape character in vips_break_token() [akemrir]
 - tiffsave has a "depth" param to set max pyr depth
+- libtiff LOGLUV images load and save as libvips XYZ 
+- add gifload_source
+- revise vipsthumbnail flags
+- add VIPS_LEAK env var
+- add vips_pipe_read_limit_set(), --vips-pipe-read-limit,
+  VIPS_PIPE_READ_LIMIT
+
+31/1/19 started 8.9.2
+- fix a deadlock with --vips-leak [DarthSim]
+- better gifload behaviour for DISPOSAL_UNSPECIFIED [DarthSim]
+- ban ppm max_value < 0 
 
 20/6/19 started 8.9.1
 - don't use the new source loaders for new_from_file or new_from_buffer, it
diff --git a/libvips/foreign/foreign.c b/libvips/foreign/foreign.c
index aec3337a..86632973 100644
--- a/libvips/foreign/foreign.c
+++ b/libvips/foreign/foreign.c
@@ -1640,9 +1640,19 @@ vips_foreign_save_build( VipsObject *object )
 			save->background ) )
 			return( -1 );
 
-		if( save->page_height )
+		if( save->page_height ) {
+			VipsImage *x;
+
+			if( vips_copy( ready, &x, NULL ) ) {
+				VIPS_UNREF( ready );
+				return( -1 );
+			}
+			VIPS_UNREF( ready );
+			ready = x;
+
 			vips_image_set_int( ready, 
 				VIPS_META_PAGE_HEIGHT, save->page_height );
+		}
 
 		VIPS_UNREF( save->ready );
 		save->ready = ready;
@@ -2097,6 +2107,7 @@ vips_foreign_operation_init( void )
 
 	extern GType vips_foreign_load_gif_file_get_type( void ); 
 	extern GType vips_foreign_load_gif_buffer_get_type( void ); 
+	extern GType vips_foreign_load_gif_source_get_type( void ); 
 
 	vips_foreign_load_csv_get_type(); 
 	vips_foreign_save_csv_get_type(); 
@@ -2148,6 +2159,7 @@ vips_foreign_operation_init( void )
 #ifdef HAVE_GIFLIB
 	vips_foreign_load_gif_file_get_type(); 
 	vips_foreign_load_gif_buffer_get_type(); 
+	vips_foreign_load_gif_source_get_type(); 
 #endif /*HAVE_GIFLIB*/
 
 #ifdef HAVE_GSF
diff --git a/libvips/foreign/gifload.c b/libvips/foreign/gifload.c
index 0ff2273b..20580e83 100644
--- a/libvips/foreign/gifload.c
+++ b/libvips/foreign/gifload.c
@@ -34,6 +34,14 @@
  * 	- check image and frame bounds, since giflib does not
  * 1/9/19
  * 	- improve early close again
+ * 30/1/19
+ * 	- rework on top of VipsSource
+ * 	- add gifload_source
+ * 31/1/20
+ * 	- treat DISPOSAL_UNSPECIFIED as _DO_NOT, since that's what many GIFs
+ * 	  in the wild appear to do
+ * 5/2/20
+ * - Fix handling of DISPOSE_BACKGROUND and DISPOSE_PREVIOUS
  */
 
 /*
@@ -108,6 +116,13 @@
 #define DISPOSE_PREVIOUS          3
 #endif
 
+
+#define NO_TRANSPARENT_INDEX      -1
+#define TRANSPARENT_MASK          0x01
+#define GIF_TRANSPARENT_COLOR     0x00ffffff
+#define DISPOSE_MASK              0x07
+#define DISPOSE_SHIFT             2
+
 #define VIPS_TYPE_FOREIGN_LOAD_GIF (vips_foreign_load_gif_get_type())
 #define VIPS_FOREIGN_LOAD_GIF( obj ) \
 	(G_TYPE_CHECK_INSTANCE_CAST( (obj), \
@@ -115,10 +130,6 @@
 #define VIPS_FOREIGN_LOAD_GIF_CLASS( klass ) \
 	(G_TYPE_CHECK_CLASS_CAST( (klass), \
 	VIPS_TYPE_FOREIGN_LOAD_GIF, VipsForeignLoadGifClass))
-#define VIPS_IS_FOREIGN_LOAD_GIF( obj ) \
-	(G_TYPE_CHECK_INSTANCE_TYPE( (obj), VIPS_TYPE_FOREIGN_LOAD_GIF ))
-#define VIPS_IS_FOREIGN_LOAD_GIF_CLASS( klass ) \
-	(G_TYPE_CHECK_CLASS_TYPE( (klass), VIPS_TYPE_FOREIGN_LOAD_GIF ))
 #define VIPS_FOREIGN_LOAD_GIF_GET_CLASS( obj ) \
 	(G_TYPE_INSTANCE_GET_CLASS( (obj), \
 	VIPS_TYPE_FOREIGN_LOAD_GIF, VipsForeignLoadGifClass ))
@@ -134,6 +145,10 @@ typedef struct _VipsForeignLoadGif {
 	 */
 	int n;
 
+	/* Load from this source (set by subclasses).
+	 */
+	VipsSource *source;
+
 	GifFileType *file;
 
 	/* We decompress the whole thing to a huge RGBA memory image, and
@@ -166,9 +181,13 @@ typedef struct _VipsForeignLoadGif {
 	 */
 	VipsImage *frame;
 
-	/* A copy of the previous frame, in case we need a DISPOSE_PREVIOUS.
-	 */
-	VipsImage *previous;
+    /* A memory scratch buffer the sized as one frame, used together with frame for rendering
+     */
+    VipsImage *scratch;
+
+    /* A copy of the previous frame, in case we need a DISPOSE_PREVIOUS.
+     */
+    VipsImage *previous;
 
 	/* The position of @frame, in pages.
 	 */
@@ -191,10 +210,10 @@ typedef struct _VipsForeignLoadGif {
 	 */
 	guint32 cmap[256];
 
-	/* As we scan the file, the index of the transparent pixel for this
-	 * frame.
-	 */
-	int transparency;
+    /* As we scan the file, the index of the transparent pixel for this
+     * frame.
+     */
+    int transparent_index;
 
 	/* Params for DGifOpen(). Set by subclasses, called by base class in
 	 * _open().
@@ -203,23 +222,7 @@ typedef struct _VipsForeignLoadGif {
 
 } VipsForeignLoadGif;
 
-typedef struct _VipsForeignLoadGifClass {
-	VipsForeignLoadClass parent_class;
-
-	/* Open the reader (eg. the FILE we are reading from). giflib is
-	 * created in _header and freed in _dispose.
-	 */
-	int (*open)( VipsForeignLoadGif *gif );
-
-	/* Rewind the reader, eg. fseek() back to the start.
-	 */
-	void (*rewind)( VipsForeignLoadGif *gif );
-
-	/* Close the reader.
-	 */
-	void (*close)( VipsForeignLoadGif *gif );
-
-} VipsForeignLoadGifClass;
+typedef VipsForeignLoadClass VipsForeignLoadGifClass;
 
 G_DEFINE_ABSTRACT_TYPE( VipsForeignLoadGif, vips_foreign_load_gif,
 	VIPS_TYPE_FOREIGN_LOAD );
@@ -318,8 +321,6 @@ vips_foreign_load_gif_error( VipsForeignLoadGif *gif )
 static int
 vips_foreign_load_gif_close_giflib( VipsForeignLoadGif *gif )
 {
-	VipsForeignLoadGifClass *class = VIPS_FOREIGN_LOAD_GIF_GET_CLASS( gif );
-
 	VIPS_DEBUG_MSG( "vips_foreign_load_gif_close_giflib:\n" );
 
 #ifdef HAVE_GIFLIB_5
@@ -346,42 +347,58 @@ vips_foreign_load_gif_close_giflib( VipsForeignLoadGif *gif )
 	}
 #endif
 
-	class->close( gif );
+	if( gif->source )
+		vips_source_minimise( gif->source );
 
 	return( 0 );
 }
 
+/* Callback from the gif loader.
+ *
+ * Read up to len bytes into buffer, return number of bytes read, 0 for EOF.
+ */
+static int
+vips_giflib_read( GifFileType *file, GifByteType *buf, int n )
+{
+	VipsForeignLoadGif *gif = (VipsForeignLoadGif *) file->UserData;
+
+	gint64 read;
+
+	read = vips_source_read( gif->source, buf, n );
+	if( read == 0 )
+		gif->eof = TRUE;
+
+	return( (int) read );
+}
+
 /* Open any underlying file resource, then giflib.
  */
 static int
 vips_foreign_load_gif_open_giflib( VipsForeignLoadGif *gif )
 {
-	VipsForeignLoadGifClass *class = VIPS_FOREIGN_LOAD_GIF_GET_CLASS( gif );
-
 	VIPS_DEBUG_MSG( "vips_foreign_load_gif_open_giflib:\n" );
 
-	if( class->open( gif ) )
-		return( -1 );
+	g_assert( !gif->file );
 
 	/* Must always rewind before opening giflib again.
 	 */
-	class->rewind( gif );
+	vips_source_rewind( gif->source );
 
 #ifdef HAVE_GIFLIB_5
 {
 	int error;
 
-	if( !(gif->file = DGifOpen( gif, gif->read_func, &error )) ) {
+	if( !(gif->file = DGifOpen( gif, vips_giflib_read, &error )) ) {
 		vips_foreign_load_gif_error_vips( gif, error );
 		(void) vips_foreign_load_gif_close_giflib( gif );
 		return( -1 );
 	}
 }
-#else 
-	if( !(gif->file = DGifOpen( gif, gif->read_func )) ) { 
-		vips_foreign_load_gif_error_vips( gif, GifLastError() ); 
+#else
+	if( !(gif->file = DGifOpen( gif, vips_giflib_read )) ) {
+		vips_foreign_load_gif_error_vips( gif, GifLastError() );
 		(void) vips_foreign_load_gif_close_giflib( gif );
-		return( -1 ); 
+		return( -1 );
 	}
 #endif
 
@@ -400,7 +417,9 @@ vips_foreign_load_gif_dispose( GObject *gobject )
 
 	vips_foreign_load_gif_close_giflib( gif );
 
+	VIPS_UNREF( gif->source );
 	VIPS_UNREF( gif->frame );
+    VIPS_UNREF( gif->scratch );
 	VIPS_UNREF( gif->previous );
 	VIPS_FREE( gif->comment );
 	VIPS_FREE( gif->line );
@@ -423,30 +442,18 @@ vips_foreign_load_gif_get_flags( VipsForeignLoad *load )
 }
 
 static gboolean
-vips_foreign_load_gif_is_a_buffer( const void *buf, size_t len )
+vips_foreign_load_gif_is_a_source( VipsSource *source )
 {
-	const guchar *str = (const guchar *) buf;
+	const unsigned char *data;
 
-	if( len >= 4 &&
-		str[0] == 'G' &&
-		str[1] == 'I' &&
-		str[2] == 'F' &&
-		str[3] == '8' )
-		return( 1 );
+	if( (data = vips_source_sniff( source, 4 )) &&
+		data[0] == 'G' &&
+		data[1] == 'I' &&
+		data[2] == 'F' &&
+		data[3] == '8' )
+		return( TRUE );
 
-	return( 0 );
-}
-
-static gboolean
-vips_foreign_load_gif_is_a( const char *filename )
-{
-	unsigned char buf[4];
-
-	if( vips__get_bytes( filename, buf, 4 ) == 4 &&
-		vips_foreign_load_gif_is_a_buffer( buf, 4 ) )
-		return( 1 );
-
-	return( 0 );
+	return( FALSE );
 }
 
 /* Make sure delays is allocated and large enough.
@@ -459,7 +466,7 @@ vips_foreign_load_gif_allocate_delays( VipsForeignLoadGif *gif )
 		int i;
 
 		gif->delays_length = gif->delays_length + gif->n_pages + 64;
-		gif->delays = (int *) g_realloc( gif->delays, 
+		gif->delays = (int *) g_realloc( gif->delays,
 			gif->delays_length * sizeof( int ) );
 		for( i = old; i < gif->delays_length; i++ )
 			gif->delays[i] = 40;
@@ -499,7 +506,7 @@ vips_foreign_load_gif_code_next( VipsForeignLoadGif *gif,
 /* Quickly scan an image record.
  */
 static int
-vips_foreign_load_gif_scan_image( VipsForeignLoadGif *gif ) 
+vips_foreign_load_gif_scan_image( VipsForeignLoadGif *gif )
 {
 	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( gif );
 	GifFileType *file = gif->file;
@@ -508,7 +515,7 @@ vips_foreign_load_gif_scan_image( VipsForeignLoadGif *gif )
 	GifByteType *extension;
 
 	if( DGifGetImageDesc( gif->file ) == GIF_ERROR ) {
-		vips_foreign_load_gif_error( gif ); 
+		vips_foreign_load_gif_error( gif );
 		return( -1 );
 	}
 
@@ -562,7 +569,8 @@ vips_foreign_load_gif_scan_application_ext( VipsForeignLoadGif *gif,
 	 */
 	have_netscape = FALSE;
 	if( extension[0] == 11 &&
-		vips_isprefix( "NETSCAPE2.0", (const char*) (extension + 1) ) )
+	   (vips_isprefix( "NETSCAPE2.0", (const char*) (extension + 1) )  ||
+        vips_isprefix( "ANIMEXTS1.0", (const char*) (extension + 1) )))
 		have_netscape = TRUE;
 
 	while( extension != NULL ) {
@@ -574,7 +582,7 @@ vips_foreign_load_gif_scan_application_ext( VipsForeignLoadGif *gif,
 			extension[0] == 3 &&
 			extension[1] == 1 ) {
 				gif->loop = extension[2] | (extension[3] << 8);
-				if( gif->loop != 0 ) 
+				if( gif->loop != 0 )
 					gif->loop += 1;
 			}
 	}
@@ -621,14 +629,14 @@ vips_foreign_load_gif_scan_extension( VipsForeignLoadGif *gif )
 		switch( ext_code ) {
 		case GRAPHICS_EXT_FUNC_CODE:
 			if( extension[0] == 4 &&
-				extension[1] & 0x1 ) {
+                extension[1] & TRANSPARENT_MASK ) {
 				VIPS_DEBUG_MSG( "gifload: has transp.\n" );
 				gif->has_transparency = TRUE;
 			}
 
 			/* giflib uses centiseconds, we use ms.
 			 */
-			gif->delays[gif->n_pages] = 
+			gif->delays[gif->n_pages] =
 				(extension[2] | (extension[3] << 8)) * 10;
 
 			while( extension != NULL )
@@ -686,16 +694,17 @@ vips_foreign_load_gif_set_header( VipsForeignLoadGif *gif, VipsImage *image )
 	 * Not the correct behavior as loop=1 became gif-loop=0
 	 * but we want to keep the old behavior untouched!
 	 */
-	vips_image_set_int( image, "gif-loop", gif->loop == 0 ? 0 : gif->loop - 1 );
+	vips_image_set_int( image,
+		"gif-loop", gif->loop == 0 ? 0 : gif->loop - 1 );
 
 	if( gif->delays ) {
 		/* The deprecated gif-delay field is in centiseconds.
 		 */
 		vips_image_set_int( image,
 			"gif-delay", VIPS_RINT( gif->delays[0] / 10.0 ) );
-		vips_image_set_array_int( image, 
+		vips_image_set_array_int( image,
 			"delay", gif->delays, gif->n_pages );
-	} 
+	}
 	else
 		vips_image_set_int( image, "gif-delay", 4 );
 
@@ -722,7 +731,7 @@ vips_foreign_load_gif_scan( VipsForeignLoadGif *gif )
 	gif->n_pages = 0;
 
 	do {
-		if( DGifGetRecordType( gif->file, &record ) == GIF_ERROR ) 
+		if( DGifGetRecordType( gif->file, &record ) == GIF_ERROR )
 			continue;
 
 		switch( record ) {
@@ -785,7 +794,7 @@ vips_foreign_load_gif_header( VipsForeignLoad *load )
 		gif->file->SWidth > VIPS_MAX_COORD ||
 		gif->file->SHeight <= 0 ||
 		gif->file->SHeight > VIPS_MAX_COORD ) {
-		vips_error( class->nickname, 
+		vips_error( class->nickname,
 			"%s", _( "image size out of bounds" ) );
 		(void) vips_foreign_load_gif_close_giflib( gif );
 
@@ -794,7 +803,7 @@ vips_foreign_load_gif_header( VipsForeignLoad *load )
 
 	/* Allocate a line buffer now that we have the GIF width.
 	 */
-	if( !(gif->line = 
+	if( !(gif->line =
 		VIPS_ARRAY( NULL, gif->file->SWidth, GifPixelType )) ||
 		vips_foreign_load_gif_scan( gif ) ||
 		vips_foreign_load_gif_set_header( gif, load->out ) ) {
@@ -838,29 +847,22 @@ vips_foreign_load_gif_build_cmap( VipsForeignLoadGif *gif )
 }
 
 static void
-vips_foreign_load_gif_render_line( VipsForeignLoadGif *gif,
-	int width, VipsPel * restrict q, VipsPel * restrict p )
+vips_foreign_load_gif_render_line( VipsForeignLoadGif *gif, int width, VipsPel * restrict dst)
 {
-	guint32 *iq;
-	int x;
+    guint32 *idst;
+    idst = (guint32 *) dst;
 
-	iq = (guint32 *) q;
-	for( x = 0; x < width; x++ ) {
-		VipsPel v = p[x];
+    int x;
+    for( x = 0; x < width; x++ ) {
 
-		if( v == gif->transparency ) {
-			/* In DISPOSE_DO_NOT mode, the previous frame shows
-			 * through (ie. we do nothing). In all other modes,
-			 * it's just transparent.
-			 */
-			if( gif->dispose != DISPOSE_DO_NOT )
-				iq[x] = 0;
-		}
-		else
-			/* Blast in the RGBA for this value.
-			 */
-			iq[x] = gif->cmap[v];
-	}
+        VipsPel v = gif->line[x];
+
+        if( v != gif->transparent_index ) {
+            /* Blast in the RGBA for this value.
+             */
+            idst[x] = gif->cmap[v];
+        }
+    }
 }
 
 /* Render the current gif frame into an RGBA buffer. GIFs can accumulate,
@@ -869,37 +871,25 @@ vips_foreign_load_gif_render_line( VipsForeignLoadGif *gif,
 static int
 vips_foreign_load_gif_render( VipsForeignLoadGif *gif )
 {
-	GifFileType *file = gif->file;
+    GifFileType *file = gif->file;
 
-	if( DGifGetImageDesc( file ) == GIF_ERROR ) {
-		vips_foreign_load_gif_error( gif );
-		return( -1 );
-	}
+    if( DGifGetImageDesc( file ) == GIF_ERROR ) {
+        vips_foreign_load_gif_error( gif );
+        return( -1 );
+    }
 
-	/* Update the colour map for this frame.
-	 */
-	vips_foreign_load_gif_build_cmap( gif );
+    /* Update the colour map for this frame.
+     */
+    vips_foreign_load_gif_build_cmap( gif );
 
-	/* BACKGROUND means we reset the frame to 0 (transparent) before we
-	 * render the next set of pixels.
-	 */
-	if( gif->dispose == DISPOSE_BACKGROUND )
-		memset( VIPS_IMAGE_ADDR( gif->frame, 0, 0 ), 0,
-			VIPS_IMAGE_SIZEOF_IMAGE( gif->frame ) );
-
-	/* PREVIOUS means we init the frame with the frame before last, ie. we
-	 * undo the last render.
-	 *
-	 * Anything other than PREVIOUS, we must update the previous buffer,
-	 */
-	if( gif->dispose == DISPOSE_PREVIOUS )
-		memcpy( VIPS_IMAGE_ADDR( gif->frame, 0, 0 ),
-			VIPS_IMAGE_ADDR( gif->previous, 0, 0 ),
-			VIPS_IMAGE_SIZEOF_IMAGE( gif->frame ) );
-	else
-		memcpy( VIPS_IMAGE_ADDR( gif->previous, 0, 0 ),
-			VIPS_IMAGE_ADDR( gif->frame, 0, 0 ),
-			VIPS_IMAGE_SIZEOF_IMAGE( gif->frame ) );
+    /* PREVIOUS means we init the frame with the last un-disposed frame. So the last un-disposed frame is used as
+     * a backdrop for the new frame.
+     */
+    if( gif->dispose == DISPOSE_PREVIOUS ) {
+        memcpy( VIPS_IMAGE_ADDR( gif->scratch, 0, 0 ),
+            VIPS_IMAGE_ADDR( gif->previous, 0, 0 ),
+            VIPS_IMAGE_SIZEOF_IMAGE( gif->scratch ) );
+    }
 
 	/* giflib does not check that the Left / Top / Width / Height for this
 	 * Image is inside the canvas.
@@ -932,50 +922,88 @@ vips_foreign_load_gif_render( VipsForeignLoadGif *gif )
 
 		for( i = 0; i < 4; i++ ) {
 			int y;
+            for( y = InterlacedOffset[i]; y < file->Image.Height; y += InterlacedJumps[i] ) {
 
-			for( y = InterlacedOffset[i];
-				y < file->Image.Height;
-			  	y += InterlacedJumps[i] ) {
-				VipsPel *q = VIPS_IMAGE_ADDR( gif->frame,
-					file->Image.Left, file->Image.Top + y );
+                if( DGifGetLine( gif->file, gif->line, file->Image.Width ) == GIF_ERROR ) {
+                    vips_foreign_load_gif_error( gif );
+                    return( -1 );
+                }
 
-				if( DGifGetLine( gif->file, gif->line,
-					file->Image.Width ) == GIF_ERROR ) {
-					vips_foreign_load_gif_error( gif );
-					return( -1 );
-				}
+                VipsPel *dst = VIPS_IMAGE_ADDR(gif->scratch, file->Image.Left, file->Image.Top + y );
 
-				vips_foreign_load_gif_render_line( gif,
-					file->Image.Width, q, gif->line );
-			}
-		}
-	}
-	else {
-		int y;
+                vips_foreign_load_gif_render_line( gif, file->Image.Width, dst );
+            }
+        }
+    }
+    else {
 
-		VIPS_DEBUG_MSG( "vips_foreign_load_gif_render: "
-			"non-interlaced frame of %d x %d pixels at %d x %d\n",
-			file->Image.Width, file->Image.Height,
-			file->Image.Left, file->Image.Top );
+        VIPS_DEBUG_MSG( "vips_foreign_load_gif_render: "
+            "non-interlaced frame of %d x %d pixels at %d x %d\n",
+            file->Image.Width, file->Image.Height,
+            file->Image.Left, file->Image.Top );
 
-		for( y = 0; y < file->Image.Height; y++ ) {
-			VipsPel *q = VIPS_IMAGE_ADDR( gif->frame,
-				file->Image.Left, file->Image.Top + y );
+        int y;
+        for( y = 0; y < file->Image.Height; y++ ) {
 
-			if( DGifGetLine( gif->file, gif->line,
-				file->Image.Width ) == GIF_ERROR ) {
-				vips_foreign_load_gif_error( gif );
-				return( -1 );
-			}
+            if( DGifGetLine( gif->file, gif->line, file->Image.Width ) == GIF_ERROR ) {
+                vips_foreign_load_gif_error( gif );
+                return( -1 );
+            }
 
-			vips_foreign_load_gif_render_line( gif,
-				file->Image.Width, q, gif->line );
-		}
-	}
+            VipsPel *dst = VIPS_IMAGE_ADDR(gif->scratch, file->Image.Left, file->Image.Top + y );
 
-	return( 0 );
+            vips_foreign_load_gif_render_line( gif, file->Image.Width, dst );
+        }
+    }
+
+    /* Copy the result to frame, which then is picked up from outside
+     */
+    memcpy( VIPS_IMAGE_ADDR( gif->frame, 0, 0 ),
+            VIPS_IMAGE_ADDR(gif->scratch, 0, 0 ),
+            VIPS_IMAGE_SIZEOF_IMAGE( gif->frame ) );
+
+    /* BACKGROUND means we reset the frame to transparent before we
+     * render the next set of pixels.
+     */
+    if( gif->dispose == DISPOSE_BACKGROUND ) {
+        int y1;
+        int x1;
+        for( y1 = file->Image.Top; y1 < file->Image.Top + file->Image.Height; y1++ ) {
+            for (x1 = file->Image.Left; x1 < file->Image.Left + file->Image.Width; x1++ ) {
+                *((guint32 *) VIPS_IMAGE_ADDR(gif->scratch, x1, y1 )) = GIF_TRANSPARENT_COLOR;
+            }
+        }
+    }
+    else if( gif->dispose == DISPOSAL_UNSPECIFIED || gif->dispose == DISPOSE_DO_NOT) {
+        /* Copy the frame to previous, so it can be restored if DISPOSE_PREVIOUS is specified in a later frame.
+         */
+        memcpy( VIPS_IMAGE_ADDR( gif->previous, 0, 0 ),
+                VIPS_IMAGE_ADDR(gif->frame, 0, 0 ),
+                VIPS_IMAGE_SIZEOF_IMAGE( gif->previous ) );
+    }
+
+    /* Reset values, as Graphic Control Extension is optional
+     */
+    gif->dispose = DISPOSAL_UNSPECIFIED;
+    gif->transparent_index = NO_TRANSPARENT_INDEX;
+
+    return( 0 );
 }
 
+#ifdef VIPS_DEBUG
+static const char *
+dispose2str( int dispose )
+{
+	switch( dispose ) {
+	case DISPOSAL_UNSPECIFIED: return( "DISPOSAL_UNSPECIFIED" );
+	case DISPOSE_DO_NOT: return( "DISPOSE_DO_NOT" );
+	case DISPOSE_BACKGROUND: return( "DISPOSE_BACKGROUND" );
+	case DISPOSE_PREVIOUS: return( "DISPOSE_PREVIOUS" );
+	default: return( "<unknown>" );
+	}
+}
+#endif /*VIPS_DEBUG*/
+
 static int
 vips_foreign_load_gif_extension( VipsForeignLoadGif *gif )
 {
@@ -993,21 +1021,25 @@ vips_foreign_load_gif_extension( VipsForeignLoadGif *gif )
 	if( extension &&
 		ext_code == GRAPHICS_EXT_FUNC_CODE &&
 		extension[0] == 4 ) {
-		/* Bytes are flags, delay low, delay high,
-		 * transparency. Flag bit 1 means transparency
-		 * is being set.
-		 */
-		gif->transparency = -1;
-		if( extension[1] & 0x1 )
-			gif->transparency = extension[4];
 
-		/* Set the current dispose mode. This is read during frame load
-		 * to set the meaning of background and transparent pixels.
-		 */
-		gif->dispose = (extension[1] >> 2) & 0x7;
+        int flags = extension[1];
+
+        /* Bytes are flags, delay low, delay high,
+         * transparency. Flag bit 1 means transparency
+         * is being set.
+         */
+        gif->transparent_index = ( flags & TRANSPARENT_MASK ) ? extension[4] : NO_TRANSPARENT_INDEX;
+        VIPS_DEBUG_MSG("vips_foreign_load_gif_extension: "
+                       "transparency = %d\n", gif->transparent_index);
+
+        /* Set the current dispose mode. This is read during frame load
+         * to set the meaning of background and transparent pixels.
+         */
+        gif->dispose = ( flags >> DISPOSE_SHIFT ) & DISPOSE_MASK;
+
 		VIPS_DEBUG_MSG( "vips_foreign_load_gif_extension: "
-			"dispose = %d\n", gif->dispose );
-	}
+			"dispose = %s\n", dispose2str( gif->dispose ) );
+    }
 
 	while( extension != NULL )
 		if( vips_foreign_load_gif_ext_next( gif, &extension ) )
@@ -1079,7 +1111,6 @@ vips_foreign_load_gif_generate( VipsRegion *or,
 {
         VipsRect *r = &or->valid;
 	VipsForeignLoadGif *gif = (VipsForeignLoadGif *) a;
-	VipsForeignLoadGifClass *class = VIPS_FOREIGN_LOAD_GIF_GET_CLASS( gif );
 
 	int y;
 
@@ -1090,11 +1121,6 @@ vips_foreign_load_gif_generate( VipsRegion *or,
 		r->left, r->top, r->width, r->height );
 #endif /*DEBUG_VERBOSE*/
 
-	/* May have been minimised. Reopen the fp if necessary.
-	 */
-	if( class->open( gif ) )
-		return( -1 );
-
 	for( y = 0; y < r->height; y++ ) {
 		/* The page for this output line, and the line number in page.
 		 */
@@ -1169,9 +1195,7 @@ vips_foreign_load_gif_generate( VipsRegion *or,
 static void
 vips_foreign_load_gif_minimise( VipsObject *object, VipsForeignLoadGif *gif )
 {
-	VipsForeignLoadGifClass *class = VIPS_FOREIGN_LOAD_GIF_GET_CLASS( gif );
-
-	class->close( gif );
+	vips_source_minimise( gif->source );
 }
 
 static int
@@ -1197,6 +1221,16 @@ vips_foreign_load_gif_load( VipsForeignLoad *load )
 	if( vips_image_write_prepare( gif->frame ) )
 		return( -1 );
 
+    /* An additional scratch buffer, same size as gif->frame. Used together with gif->frame for rendering.
+     */
+    gif->scratch = vips_image_new_memory();
+    vips_image_init_fields( gif->scratch,
+                            gif->file->SWidth, gif->file->SHeight, 4, VIPS_FORMAT_UCHAR,
+                            VIPS_CODING_NONE, VIPS_INTERPRETATION_sRGB, 1.0, 1.0 );
+    if( vips_image_write_prepare( gif->scratch ) )
+        return( -1 );
+
+
 	/* A copy of the previous state of the frame, in case we have to
 	 * process a DISPOSE_PREVIOUS.
 	 */
@@ -1215,8 +1249,8 @@ vips_foreign_load_gif_load( VipsForeignLoad *load )
 
 	/* Close input immediately at end of read.
 	 */
-	g_signal_connect( t[0], "minimise", 
-		G_CALLBACK( vips_foreign_load_gif_minimise ), gif ); 
+	g_signal_connect( t[0], "minimise",
+		G_CALLBACK( vips_foreign_load_gif_minimise ), gif );
 
 	/* Strips 8 pixels high to avoid too many tiny regions.
 	 */
@@ -1231,22 +1265,6 @@ vips_foreign_load_gif_load( VipsForeignLoad *load )
 	return( 0 );
 }
 
-static int
-vips_foreign_load_gif_open( VipsForeignLoadGif *gif )
-{
-	return( 0 );
-}
-
-static void
-vips_foreign_load_gif_rewind( VipsForeignLoadGif *gif )
-{
-}
-
-static void
-vips_foreign_load_gif_close( VipsForeignLoadGif *gif )
-{
-}
-
 static void
 vips_foreign_load_gif_class_init( VipsForeignLoadGifClass *class )
 {
@@ -1267,10 +1285,6 @@ vips_foreign_load_gif_class_init( VipsForeignLoadGifClass *class )
 		vips_foreign_load_gif_get_flags_filename;
 	load_class->get_flags = vips_foreign_load_gif_get_flags;
 
-	class->open = vips_foreign_load_gif_open;
-	class->rewind = vips_foreign_load_gif_rewind;
-	class->close = vips_foreign_load_gif_close;
-
 	VIPS_ARG_INT( class, "page", 20,
 		_( "Page" ),
 		_( "Load this page from the file" ),
@@ -1290,13 +1304,13 @@ vips_foreign_load_gif_class_init( VipsForeignLoadGifClass *class )
 static void
 vips_foreign_load_gif_init( VipsForeignLoadGif *gif )
 {
-	gif->n = 1;
-	gif->transparency = -1;
+    gif->n = 1;
+    gif->transparent_index = NO_TRANSPARENT_INDEX;
 	gif->delays = NULL;
 	gif->delays_length = 0;
 	gif->loop = 1;
 	gif->comment = NULL;
-	gif->dispose = 0;
+    gif->dispose = DISPOSAL_UNSPECIFIED;
 
 	vips_foreign_load_gif_allocate_delays( gif );
 }
@@ -1308,14 +1322,6 @@ typedef struct _VipsForeignLoadGifFile {
 	 */
 	char *filename;
 
-	/* The FILE* we read from.
-	 */
-	FILE *fp;
-
-	/* If we close and reopen, save the ftell point here.
-	 */
-	long seek_position;
-
 } VipsForeignLoadGifFile;
 
 typedef VipsForeignLoadGifClass VipsForeignLoadGifFileClass;
@@ -1323,82 +1329,22 @@ typedef VipsForeignLoadGifClass VipsForeignLoadGifFileClass;
 G_DEFINE_TYPE( VipsForeignLoadGifFile, vips_foreign_load_gif_file,
 	vips_foreign_load_gif_get_type() );
 
-/* Our input function for file open. We can't use DGifOpenFileName(), since
- * that just calls open() and won't work with unicode on win32. We can't use
- * DGifOpenFileHandle() since that's an fd from open() and you can't pass those
- * across DLL boundaries on Windows.
- */
-static int 
-vips_giflib_file_read( GifFileType *gfile, GifByteType *buffer, int n )
-{
-	VipsForeignLoadGif *gif = (VipsForeignLoadGif *) gfile->UserData;
-	VipsForeignLoadGifFile *file = (VipsForeignLoadGifFile *) gif;
-
-	if( feof( file->fp ) )
-		gif->eof = TRUE;
-
-	return( (int) fread( (void *) buffer, 1, n, file->fp ) );
-}
-
-/* We have to have _open() as a vfunc since we want to be able to reopen in
- * _generate if we have been closed during _minimise. 
- */
 static int
-vips_foreign_load_gif_file_open( VipsForeignLoadGif *gif )
+vips_foreign_load_gif_file_build( VipsObject *object )
 {
-	VipsForeignLoad *load = (VipsForeignLoad *) gif;
-	VipsForeignLoadGifFile *file = (VipsForeignLoadGifFile *) gif;
+	VipsForeignLoadGifFile *file = (VipsForeignLoadGifFile *) object;
+	VipsForeignLoadGif *gif = (VipsForeignLoadGif *) object;
 
-	VIPS_DEBUG_MSG( "vips_foreign_load_gif_file_open:\n" );
-
-	if( !file->fp ) {
-		if( !(file->fp =
-			vips__file_open_read( file->filename, NULL, FALSE )) )
+	if( file->filename )
+		if( !(gif->source =
+			vips_source_new_from_file( file->filename )) )
 			return( -1 );
 
-		/* Restore the read point if we are reopening.
-		 */
-		if( file->seek_position != -1 )
-			fseek( file->fp, file->seek_position, SEEK_SET );
+	if( VIPS_OBJECT_CLASS( vips_foreign_load_gif_file_parent_class )->
+		build( object ) )
+		return( -1 );
 
-		VIPS_SETSTR( load->out->filename, file->filename );
-		gif->read_func = vips_giflib_file_read;
-	}
-
-	return( VIPS_FOREIGN_LOAD_GIF_CLASS(
-		vips_foreign_load_gif_file_parent_class )->open( gif ) );
-}
-
-static void
-vips_foreign_load_gif_file_rewind( VipsForeignLoadGif *gif )
-{
-	VipsForeignLoadGifFile *file = (VipsForeignLoadGifFile *) gif;
-
-	VIPS_DEBUG_MSG( "vips_foreign_load_gif_file_rewind:\n" );
-
-	if( file->fp ) {
-		file->seek_position = 0;
-		fseek( file->fp, file->seek_position, SEEK_SET );
-	}
-
-	VIPS_FOREIGN_LOAD_GIF_CLASS(
-		vips_foreign_load_gif_file_parent_class )->rewind( gif );
-}
-
-static void
-vips_foreign_load_gif_file_close( VipsForeignLoadGif *gif )
-{
-	VipsForeignLoadGifFile *file = (VipsForeignLoadGifFile *) gif;
-
-	VIPS_DEBUG_MSG( "vips_foreign_load_gif_file_close:\n" );
-
-	if( file->fp ) {
-		file->seek_position = ftell( file->fp );
-		VIPS_FREEF( fclose, file->fp );
-	}
-
-	VIPS_FOREIGN_LOAD_GIF_CLASS(
-		vips_foreign_load_gif_file_parent_class )->close( gif );
+	return( 0 );
 }
 
 static const char *vips_foreign_gif_suffs[] = {
@@ -1406,6 +1352,20 @@ static const char *vips_foreign_gif_suffs[] = {
 	NULL
 };
 
+static gboolean
+vips_foreign_load_gif_file_is_a( const char *filename )
+{
+	VipsSource *source;
+	gboolean result;
+
+	if( !(source = vips_source_new_from_file( filename )) )
+		return( FALSE );
+	result = vips_foreign_load_gif_is_a_source( source );
+	VIPS_UNREF( source );
+
+	return( result );
+}
+
 static void
 vips_foreign_load_gif_file_class_init(
 	VipsForeignLoadGifFileClass *class )
@@ -1414,21 +1374,17 @@ vips_foreign_load_gif_file_class_init(
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
 	VipsForeignClass *foreign_class = (VipsForeignClass *) class;
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
-	VipsForeignLoadGifClass *gif_class = (VipsForeignLoadGifClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
 	gobject_class->get_property = vips_object_get_property;
 
 	object_class->nickname = "gifload";
 	object_class->description = _( "load GIF with giflib" );
+	object_class->build = vips_foreign_load_gif_file_build;
 
 	foreign_class->suffs = vips_foreign_gif_suffs;
 
-	load_class->is_a = vips_foreign_load_gif_is_a;
-
-	gif_class->open = vips_foreign_load_gif_file_open;
-	gif_class->rewind = vips_foreign_load_gif_file_rewind;
-	gif_class->close = vips_foreign_load_gif_file_close;
+	load_class->is_a = vips_foreign_load_gif_file_is_a;
 
 	VIPS_ARG_STRING( class, "filename", 1,
 		_( "Filename" ),
@@ -1442,7 +1398,6 @@ vips_foreign_load_gif_file_class_init(
 static void
 vips_foreign_load_gif_file_init( VipsForeignLoadGifFile *file )
 {
-	file->seek_position = -1;
 }
 
 typedef struct _VipsForeignLoadGifBuffer {
@@ -1450,12 +1405,7 @@ typedef struct _VipsForeignLoadGifBuffer {
 
 	/* Load from a buffer.
 	 */
-	VipsArea *buf;
-
-	/* Current read point, bytes left in buffer.
-	 */
-	VipsPel *p;
-	size_t bytes_to_go;
+	VipsArea *blob;
 
 } VipsForeignLoadGifBuffer;
 
@@ -1464,59 +1414,38 @@ typedef VipsForeignLoadGifClass VipsForeignLoadGifBufferClass;
 G_DEFINE_TYPE( VipsForeignLoadGifBuffer, vips_foreign_load_gif_buffer,
 	vips_foreign_load_gif_get_type() );
 
-/* Callback from the gif loader.
- *
- * Read up to len bytes into buffer, return number of bytes read, 0 for EOF.
- */
 static int
-vips_giflib_buffer_read( GifFileType *file, GifByteType *buf, int n )
+vips_foreign_load_gif_buffer_build( VipsObject *object )
 {
-	VipsForeignLoadGif *gif = (VipsForeignLoadGif *) file->UserData;
-	VipsForeignLoadGifBuffer *buffer = (VipsForeignLoadGifBuffer *) gif;
-	size_t will_read = VIPS_MIN( n, buffer->bytes_to_go );
+	VipsForeignLoadGif *gif = (VipsForeignLoadGif *) object;
+	VipsForeignLoadGifBuffer *buffer =
+		(VipsForeignLoadGifBuffer *) object;
 
-	memcpy( buf, buffer->p, will_read );
-	buffer->p += will_read;
-	buffer->bytes_to_go -= will_read;
+	if( buffer->blob &&
+		!(gif->source = vips_source_new_from_memory(
+			VIPS_AREA( buffer->blob )->data,
+			VIPS_AREA( buffer->blob )->length )) )
+		return( -1 );
 
-	if( will_read == 0 )
-		gif->eof = TRUE;
+	if( VIPS_OBJECT_CLASS( vips_foreign_load_gif_buffer_parent_class )->
+		build( object ) )
+		return( -1 );
 
-	return( will_read ); 
+	return( 0 );
 }
 
-static int
-vips_foreign_load_gif_buffer_open( VipsForeignLoadGif *gif )
+static gboolean
+vips_foreign_load_gif_buffer_is_a_buffer( const void *buf, size_t len )
 {
-	VipsForeignLoadGifBuffer *buffer = (VipsForeignLoadGifBuffer *) gif;
+	VipsSource *source;
+	gboolean result;
 
-	VIPS_DEBUG_MSG( "vips_foreign_load_gif_buffer_open:\n" );
+	if( !(source = vips_source_new_from_memory( buf, len )) )
+		return( FALSE );
+	result = vips_foreign_load_gif_is_a_source( source );
+	VIPS_UNREF( source );
 
-	/* We can open several times -- make sure we don't move the read point
-	 * if we reopen.
-	 */
-	if( !buffer->p ) {
-		buffer->p = buffer->buf->data;
-		buffer->bytes_to_go = buffer->buf->length;
-		gif->read_func = vips_giflib_buffer_read;
-	}
-
-	return( VIPS_FOREIGN_LOAD_GIF_CLASS(
-		vips_foreign_load_gif_buffer_parent_class )->open( gif ) );
-}
-
-static void
-vips_foreign_load_gif_buffer_rewind( VipsForeignLoadGif *gif )
-{
-	VipsForeignLoadGifBuffer *buffer = (VipsForeignLoadGifBuffer *) gif;
-
-	VIPS_DEBUG_MSG( "vips_foreign_load_gif_buffer_rewind:\n" );
-
-	buffer->p = buffer->buf->data;
-	buffer->bytes_to_go = buffer->buf->length;
-
-	VIPS_FOREIGN_LOAD_GIF_CLASS(
-		vips_foreign_load_gif_buffer_parent_class )->rewind( gif );
+	return( result );
 }
 
 static void
@@ -1526,24 +1455,21 @@ vips_foreign_load_gif_buffer_class_init(
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
-	VipsForeignLoadGifClass *gif_class = (VipsForeignLoadGifClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
 	gobject_class->get_property = vips_object_get_property;
 
 	object_class->nickname = "gifload_buffer";
 	object_class->description = _( "load GIF with giflib" );
+	object_class->build = vips_foreign_load_gif_buffer_build;
 
-	load_class->is_a_buffer = vips_foreign_load_gif_is_a_buffer;
-
-	gif_class->open = vips_foreign_load_gif_buffer_open;
-	gif_class->rewind = vips_foreign_load_gif_buffer_rewind;
+	load_class->is_a_buffer = vips_foreign_load_gif_buffer_is_a_buffer;
 
 	VIPS_ARG_BOXED( class, "buffer", 1,
 		_( "Buffer" ),
 		_( "Buffer to load from" ),
 		VIPS_ARGUMENT_REQUIRED_INPUT,
-		G_STRUCT_OFFSET( VipsForeignLoadGifBuffer, buf ),
+		G_STRUCT_OFFSET( VipsForeignLoadGifBuffer, blob ),
 		VIPS_TYPE_BLOB );
 
 }
@@ -1553,6 +1479,70 @@ vips_foreign_load_gif_buffer_init( VipsForeignLoadGifBuffer *buffer )
 {
 }
 
+typedef struct _VipsForeignLoadGifSource {
+	VipsForeignLoadGif parent_object;
+
+	/* Load from a source.
+	 */
+	VipsSource *source;
+
+} VipsForeignLoadGifSource;
+
+typedef VipsForeignLoadGifClass VipsForeignLoadGifSourceClass;
+
+G_DEFINE_TYPE( VipsForeignLoadGifSource, vips_foreign_load_gif_source,
+	vips_foreign_load_gif_get_type() );
+
+static int
+vips_foreign_load_gif_source_build( VipsObject *object )
+{
+	VipsForeignLoadGif *gif = (VipsForeignLoadGif *) object;
+	VipsForeignLoadGifSource *source =
+		(VipsForeignLoadGifSource *) object;
+
+	if( source->source ) {
+		gif->source = source->source;
+		g_object_ref( gif->source );
+	}
+
+	if( VIPS_OBJECT_CLASS( vips_foreign_load_gif_source_parent_class )->
+		build( object ) )
+		return( -1 );
+
+	return( 0 );
+}
+
+static void
+vips_foreign_load_gif_source_class_init(
+	VipsForeignLoadGifSourceClass *class )
+{
+	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
+	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
+
+	gobject_class->set_property = vips_object_set_property;
+	gobject_class->get_property = vips_object_get_property;
+
+	object_class->nickname = "gifload_source";
+	object_class->description = _( "load GIF with giflib" );
+	object_class->build = vips_foreign_load_gif_source_build;
+
+	load_class->is_a_source = vips_foreign_load_gif_is_a_source;
+
+	VIPS_ARG_OBJECT( class, "source", 1,
+		_( "Source" ),
+		_( "Source to load from" ),
+		VIPS_ARGUMENT_REQUIRED_INPUT,
+		G_STRUCT_OFFSET( VipsForeignLoadGifSource, source ),
+		VIPS_TYPE_SOURCE );
+
+}
+
+static void
+vips_foreign_load_gif_source_init( VipsForeignLoadGifSource *source )
+{
+}
+
 #endif /*HAVE_GIFLIB*/
 
 /**
@@ -1637,3 +1627,32 @@ vips_gifload_buffer( void *buf, size_t len, VipsImage **out, ... )
 	return( result );
 }
 
+/**
+ * vips_gifload_source:
+ * @source: source to load
+ * @out: (out): image to write
+ * @...: %NULL-terminated list of optional named arguments
+ *
+ * Optional arguments:
+ *
+ * * @page: %gint, page (frame) to read
+ * * @n: %gint, load this many pages
+ *
+ * Exactly as vips_gifload(), but read from a source.
+ *
+ * See also: vips_gifload().
+ *
+ * Returns: 0 on success, -1 on error.
+ */
+int
+vips_gifload_source( VipsSource *source, VipsImage **out, ... )
+{
+	va_list ap;
+	int result;
+
+	va_start( ap, out );
+	result = vips_call_split( "gifload_source", ap, source, out );
+	va_end( ap );
+
+	return( result );
+}
diff --git a/libvips/foreign/ppmload.c b/libvips/foreign/ppmload.c
index 78709f4b..6df91058 100644
--- a/libvips/foreign/ppmload.c
+++ b/libvips/foreign/ppmload.c
@@ -35,6 +35,8 @@
  * 	- redone with source/target
  * 	- sequential load, plus mmap for filename sources
  * 	- faster plus lower memory use
+ * 02/02/2020
+ * 	- ban max_vaue < 0 
  */
 
 /*
@@ -259,6 +261,12 @@ vips_foreign_load_ppm_parse_header( VipsForeignLoadPpm *ppm )
 			if( get_int( ppm->sbuf, &ppm->max_value ) )
 				return( -1 );
 
+			/* max_value must be > 0 and <= 65535, according to
+			 * the spec, but we allow up to 32 bits per pixel.
+			 */
+			if( ppm->max_value < 0 )
+				ppm->max_value = 0;
+
 			if( ppm->max_value > 255 )
 				ppm->bits = 16;
 			if( ppm->max_value > 65535 )
diff --git a/libvips/foreign/tiff2vips.c b/libvips/foreign/tiff2vips.c
index 56935afb..c8b7873e 100644
--- a/libvips/foreign/tiff2vips.c
+++ b/libvips/foreign/tiff2vips.c
@@ -193,6 +193,8 @@
  * 	- switch to source input
  * 18/11/19
  * 	- support ASSOCALPHA in any alpha band
+ * 27/1/20
+ * 	- read logluv images as XYZ
  */
 
 /*
@@ -294,6 +296,10 @@ typedef struct _RtiffHeader {
 	 */
 	uint32 read_height;
 	tsize_t read_size;
+
+	/* Scale factor to get absolute cd/m2 from XYZ.
+	 */
+	double stonits;
 } RtiffHeader;
 
 /* Scanline-type process function.
@@ -911,6 +917,52 @@ rtiff_parse_labs( Rtiff *rtiff, VipsImage *out )
 	return( 0 );
 }
 
+/* libtiff delivers logluv as illuminant-free 0-1 XYZ in 3 x float.
+ */
+static void
+rtiff_logluv_line( Rtiff *rtiff, VipsPel *q, VipsPel *p, int n, void *dummy )
+{
+	int samples_per_pixel = rtiff->header.samples_per_pixel;
+
+	float *p1;
+	float *q1;
+	int x;
+	int i; 
+
+	p1 = (float *) p;
+	q1 = (float *) q;
+	for( x = 0; x < n; x++ ) {
+		q1[0] = VIPS_D65_X0 * p1[0];
+		q1[1] = VIPS_D65_Y0 * p1[1];
+		q1[2] = VIPS_D65_Z0 * p1[2];
+
+		for( i = 3; i < samples_per_pixel; i++ ) 
+			q1[i] = p1[i];
+
+		q1 += samples_per_pixel;
+		p1 += samples_per_pixel;
+	}
+}
+
+/* LOGLUV images arrive from libtiff as float xyz.
+ */
+static int
+rtiff_parse_logluv( Rtiff *rtiff, VipsImage *out )
+{
+	if( rtiff_check_min_samples( rtiff, 3 ) ||
+		rtiff_check_interpretation( rtiff, PHOTOMETRIC_LOGLUV ) )
+		return( -1 );
+
+	out->Bands = rtiff->header.samples_per_pixel; 
+	out->BandFmt = VIPS_FORMAT_FLOAT; 
+	out->Coding = VIPS_CODING_NONE; 
+	out->Type = VIPS_INTERPRETATION_XYZ; 
+
+	rtiff->sfn = rtiff_logluv_line;
+
+	return( 0 );
+}
+
 /* Per-scanline process function for 1 bit images.
  */
 static void
@@ -1406,6 +1458,9 @@ rtiff_pick_reader( Rtiff *rtiff )
 			return( rtiff_parse_labs );
 	}
 
+	if( photometric_interpretation == PHOTOMETRIC_LOGLUV ) 
+		return( rtiff_parse_logluv );
+
 	if( photometric_interpretation == PHOTOMETRIC_MINISWHITE ||
 		photometric_interpretation == PHOTOMETRIC_MINISBLACK ) {
 		if( bits_per_sample == 1 )
@@ -1436,6 +1491,15 @@ rtiff_set_header( Rtiff *rtiff, VipsImage *out )
 		TIFFSetField( rtiff->tiff, 
 			TIFFTAG_JPEGCOLORMODE, JPEGCOLORMODE_RGB );
 
+	/* Ask for LOGLUV as 3 x float XYZ. 
+	 */
+	if( rtiff->header.photometric_interpretation == PHOTOMETRIC_LOGLUV ) {
+		TIFFSetField( rtiff->tiff, 
+			TIFFTAG_SGILOGDATAFMT, SGILOGDATAFMT_FLOAT );
+
+		vips_image_set_double( out, "stonits", rtiff->header.stonits );
+	}
+
 	out->Xsize = rtiff->header.width;
 	out->Ysize = rtiff->header.height * rtiff->n;
 
@@ -2104,7 +2168,7 @@ rtiff_read_stripwise( Rtiff *rtiff, VipsImage *out )
 	/* Double check: in memcpy mode, the vips linesize should exactly
 	 * match the tiff line size.
 	 */
-	if( rtiff->memcpy ) {
+	if( rtiff->memcpy ) { 
 		size_t vips_line_size;
 
 		/* Lines are smaller in plane-separated mode.
@@ -2198,13 +2262,15 @@ rtiff_header_read( Rtiff *rtiff, RtiffHeader *header )
 
 	TIFFGetFieldDefaulted( rtiff->tiff, 
 		TIFFTAG_COMPRESSION, &header->compression );
+
+	/* Request YCbCr expansion. libtiff complains if you do this for
+	 * non-jpg images. We must set this here since it changes the result
+	 * of scanline_size.
+	 */
 	if( header->compression == COMPRESSION_JPEG )
-		/* We want to always expand subsampled YCBCR images to full 
-		 * RGB. 
-		 */
 		TIFFSetField( rtiff->tiff, 
 			TIFFTAG_JPEGCOLORMODE, JPEGCOLORMODE_RGB );
-        else if( header->photometric_interpretation == PHOTOMETRIC_YCBCR ) {
+	else if( header->photometric_interpretation == PHOTOMETRIC_YCBCR ) {
 		/* We rely on the jpg decompressor to upsample chroma
 		 * subsampled images. If there is chroma subsampling but
 		 * no jpg compression, we have to give up.
@@ -2223,6 +2289,26 @@ rtiff_header_read( Rtiff *rtiff, RtiffHeader *header )
                 }
         }
 
+	if( header->photometric_interpretation == PHOTOMETRIC_LOGLUV ) {
+		if( header->compression != COMPRESSION_SGILOG &&
+			header->compression != COMPRESSION_SGILOG24 ) {
+			vips_error( "tiff2vips",
+				"%s", _( "not SGI-compressed LOGLUV" ) );
+			return( -1 );
+		}
+
+		/* Always get LOGLUV as 3 x float XYZ. We must set this here 
+		 * since it'll change the value of scanline_size.
+		 */
+		TIFFSetField( rtiff->tiff, 
+			TIFFTAG_SGILOGDATAFMT, SGILOGDATAFMT_FLOAT );
+	}
+
+	/* For logluv, the calibration factor to get to absolute luminance.
+	 */
+	if( !TIFFGetField( rtiff->tiff, TIFFTAG_STONITS, &header->stonits ) )
+		header->stonits = 1.0;
+
 	/* Arbitrary sanity-checking limits.
 	 */
 	if( header->width <= 0 ||
diff --git a/libvips/foreign/tiffload.c b/libvips/foreign/tiffload.c
index 70950410..20b2b094 100644
--- a/libvips/foreign/tiffload.c
+++ b/libvips/foreign/tiffload.c
@@ -389,7 +389,7 @@ vips_foreign_load_tiff_buffer_build( VipsObject *object )
 			VIPS_AREA( buffer->blob )->length )) )
 		return( -1 );
 
-	if( VIPS_OBJECT_CLASS( vips_foreign_load_tiff_file_parent_class )->
+	if( VIPS_OBJECT_CLASS( vips_foreign_load_tiff_buffer_parent_class )->
 		build( object ) )
 		return( -1 );
 
@@ -456,8 +456,8 @@ vips_foreign_load_tiff_buffer_init( VipsForeignLoadTiffBuffer *buffer )
  *   during load
  *
  * Read a TIFF file into a VIPS image. It is a full baseline TIFF 6 reader, 
- * with extensions for tiled images, multipage images, LAB colour space, 
- * pyramidal images and JPEG compression. including CMYK and YCbCr.
+ * with extensions for tiled images, multipage images, XYZ and LAB colour 
+ * space, pyramidal images and JPEG compression, including CMYK and YCbCr.
  *
  * @page means load this page from the file. By default the first page (page
  * 0) is read. 
diff --git a/libvips/foreign/tiffsave.c b/libvips/foreign/tiffsave.c
index 281d486a..8644a820 100644
--- a/libvips/foreign/tiffsave.c
+++ b/libvips/foreign/tiffsave.c
@@ -551,6 +551,10 @@ vips_foreign_save_tiff_buffer_init( VipsForeignSaveTiffBuffer *buffer )
  * good for 1-bit images, and deflate is the best lossless compression TIFF 
  * can do. 
  *
+ * XYZ images are automatically saved as libtiff LOGLUV with SGILOG compression.
+ * Float LAB images are saved as float CIELAB. Set @squash to save as 8-bit 
+ * CIELAB.
+ *
  * Use @Q to set the JPEG compression factor. Default 75.
  *
  * User @level to set the ZSTD compression level. Use @lossless to
diff --git a/libvips/foreign/vips2tiff.c b/libvips/foreign/vips2tiff.c
index 63e338ac..0edcbe7e 100644
--- a/libvips/foreign/vips2tiff.c
+++ b/libvips/foreign/vips2tiff.c
@@ -189,6 +189,8 @@
  * 	- "squash" now squashes 3-band float LAB down to LABQ
  * 26/1/20
  * 	- add "depth" to set pyr depth
+ * 27/1/20
+ * 	- write XYZ images as logluv
  */
 
 /*
@@ -608,7 +610,6 @@ wtiff_write_header( Wtiff *wtiff, Layer *layer )
 {
 	TIFF *tif = layer->tif;
 
-	int format; 
 	int orientation; 
 
 	/* Output base header fields.
@@ -702,6 +703,21 @@ wtiff_write_header( Wtiff *wtiff, Layer *layer )
 			photometric = PHOTOMETRIC_CIELAB;
 			colour_bands = 3;
 		}
+		else if( wtiff->input->Type == VIPS_INTERPRETATION_XYZ ) { 
+			double stonits;
+
+			photometric = PHOTOMETRIC_LOGLUV;
+			/* Tell libtiff we will write as float XYZ.
+			 */
+			TIFFSetField( tif, 
+				TIFFTAG_SGILOGDATAFMT, SGILOGDATAFMT_FLOAT );
+			stonits = 1.0;
+			if( vips_image_get_typeof( wtiff->ready, "stonits" ) )
+				vips_image_get_double( wtiff->ready, 
+					"stonits", &stonits );
+			TIFFSetField( tif, TIFFTAG_STONITS, stonits );
+			colour_bands = 3;
+		}
 		else if( wtiff->ready->Type == VIPS_INTERPRETATION_CMYK &&
 			wtiff->ready->Bands >= 4 ) {
 			photometric = PHOTOMETRIC_SEPARATED;
@@ -764,17 +780,23 @@ wtiff_write_header( Wtiff *wtiff, Layer *layer )
 		TIFFSetField( tif, TIFFTAG_SUBFILETYPE, FILETYPE_REDUCEDIMAGE );
 
 	/* Sample format.
+	 *
+	 * Don't set for logluv: libtiff does this for us.
 	 */
-	format = SAMPLEFORMAT_UINT;
-	if( vips_band_format_isuint( wtiff->ready->BandFmt ) )
+	if( wtiff->input->Type != VIPS_INTERPRETATION_XYZ ) { 
+		int format; 
+
 		format = SAMPLEFORMAT_UINT;
-	else if( vips_band_format_isint( wtiff->ready->BandFmt ) )
-		format = SAMPLEFORMAT_INT;
-	else if( vips_band_format_isfloat( wtiff->ready->BandFmt ) )
-		format = SAMPLEFORMAT_IEEEFP;
-	else if( vips_band_format_iscomplex( wtiff->ready->BandFmt ) )
-		format = SAMPLEFORMAT_COMPLEXIEEEFP;
-	TIFFSetField( tif, TIFFTAG_SAMPLEFORMAT, format );
+		if( vips_band_format_isuint( wtiff->ready->BandFmt ) )
+			format = SAMPLEFORMAT_UINT;
+		else if( vips_band_format_isint( wtiff->ready->BandFmt ) )
+			format = SAMPLEFORMAT_INT;
+		else if( vips_band_format_isfloat( wtiff->ready->BandFmt ) )
+			format = SAMPLEFORMAT_IEEEFP;
+		else if( vips_band_format_iscomplex( wtiff->ready->BandFmt ) )
+			format = SAMPLEFORMAT_COMPLEXIEEEFP;
+		TIFFSetField( tif, TIFFTAG_SAMPLEFORMAT, format );
+	}
 
 	return( 0 );
 }
@@ -1039,6 +1061,11 @@ wtiff_new( VipsImage *input, const char *filename,
 		return( NULL );
 	}
 
+	/* XYZ images are written as libtiff LOGLUV.
+	 */
+	if( wtiff->ready->Type == VIPS_INTERPRETATION_XYZ ) 
+		wtiff->compression = COMPRESSION_SGILOG;
+
 	/* Multipage image?
 	 */
 	if( wtiff->page_height < wtiff->ready->Ysize ) {
@@ -1331,6 +1358,31 @@ LabS2Lab16( VipsPel *q, VipsPel *p, int n, int samples_per_pixel )
 	}
 }
 
+/* Convert VIPS D65 XYZ to TIFF scaled float illuminant-free xyz.
+ */
+static void
+XYZ2tiffxyz( VipsPel *q, VipsPel *p, int n, int samples_per_pixel )
+{
+	float *p1 = (float *) p;
+	float *q1 = (float *) q;
+
+	int x;
+
+        for( x = 0; x < n; x++ ) {
+		int i;
+
+                q1[0] = p1[0] / VIPS_D65_X0;
+                q1[1] = p1[1] / VIPS_D65_Y0;
+                q1[2] = p1[2] / VIPS_D65_Z0;
+
+		for( i = 3; 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.
  */
 static void
@@ -1358,6 +1410,8 @@ wtiff_pack2tiff( Wtiff *wtiff, Layer *layer,
 			LabQ2LabC( q, p, area->width );
 		else if( wtiff->squash ) 
 			eightbit2onebit( wtiff, q, p, area->width );
+		else if( wtiff->input->Type == VIPS_INTERPRETATION_XYZ )
+			XYZ2tiffxyz( q, p, area->width, in->im->Bands );
 		else if( (in->im->Bands == 1 || in->im->Bands == 2) && 
 			wtiff->miniswhite ) 
 			invert_band0( wtiff, q, p, area->width );
@@ -1449,6 +1503,10 @@ wtiff_layer_write_strip( Wtiff *wtiff, Layer *layer, VipsRegion *strip )
 			LabS2Lab16( wtiff->tbuf, p, im->Xsize, im->Bands );
 			p = wtiff->tbuf;
 		}
+		else if( wtiff->input->Type == VIPS_INTERPRETATION_XYZ ) {
+			XYZ2tiffxyz( wtiff->tbuf, p, im->Xsize, im->Bands );
+			p = wtiff->tbuf;
+		}
 		else if( wtiff->squash ) {
 			eightbit2onebit( wtiff, wtiff->tbuf, p, im->Xsize );
 			p = wtiff->tbuf;
diff --git a/libvips/include/vips/connection.h b/libvips/include/vips/connection.h
index 66cd5474..d12a33a6 100644
--- a/libvips/include/vips/connection.h
+++ b/libvips/include/vips/connection.h
@@ -89,6 +89,8 @@ GType vips_connection_get_type( void );
 const char *vips_connection_filename( VipsConnection *connection );
 const char *vips_connection_nick( VipsConnection *connection );
 
+void vips_pipe_read_limit_set( gint64 limit );
+
 #define VIPS_TYPE_SOURCE (vips_source_get_type())
 #define VIPS_SOURCE( obj ) \
 	(G_TYPE_CHECK_INSTANCE_CAST( (obj), \
diff --git a/libvips/include/vips/foreign.h b/libvips/include/vips/foreign.h
index 2447b3d1..1f84f4f9 100644
--- a/libvips/include/vips/foreign.h
+++ b/libvips/include/vips/foreign.h
@@ -597,6 +597,8 @@ int vips_gifload( const char *filename, VipsImage **out, ... )
 	__attribute__((sentinel));
 int vips_gifload_buffer( void *buf, size_t len, VipsImage **out, ... )
 	__attribute__((sentinel));
+int vips_gifload_source( VipsSource *source, VipsImage **out, ... )
+	__attribute__((sentinel));
 
 int vips_heifload( const char *filename, VipsImage **out, ... )
 	__attribute__((sentinel));
diff --git a/libvips/include/vips/private.h b/libvips/include/vips/private.h
index e28735fc..8716cf36 100644
--- a/libvips/include/vips/private.h
+++ b/libvips/include/vips/private.h
@@ -192,6 +192,8 @@ int vips__view_image( struct _VipsImage *image );
  */
 extern int _vips__argument_id;
 
+void vips__meta_init( void );
+
 #ifdef __cplusplus
 }
 #endif /*__cplusplus*/
diff --git a/libvips/include/vips/region.h b/libvips/include/vips/region.h
index bcce3c47..d52a3fa7 100644
--- a/libvips/include/vips/region.h
+++ b/libvips/include/vips/region.h
@@ -62,6 +62,7 @@ extern "C" {
  * @VIPS_REGION_SHRINK_MODE: use the mode
  * @VIPS_REGION_SHRINK_MAX: use the maximum
  * @VIPS_REGION_SHRINK_MIN: use the minimum
+ * @VIPS_REGION_SHRINK_NEAREST: use the top-left pixel
  *
  * How to calculate the output pixels when shrinking a 2x2 region.
  */
@@ -71,6 +72,7 @@ typedef enum {
 	VIPS_REGION_SHRINK_MODE,
 	VIPS_REGION_SHRINK_MAX,
 	VIPS_REGION_SHRINK_MIN,
+	VIPS_REGION_SHRINK_NEAREST,
 	VIPS_REGION_SHRINK_LAST
 } VipsRegionShrink;
 
diff --git a/libvips/iofuncs/enumtypes.c b/libvips/iofuncs/enumtypes.c
index 2f571331..767a43f9 100644
--- a/libvips/iofuncs/enumtypes.c
+++ b/libvips/iofuncs/enumtypes.c
@@ -905,6 +905,7 @@ vips_region_shrink_get_type( void )
 			{VIPS_REGION_SHRINK_MODE, "VIPS_REGION_SHRINK_MODE", "mode"},
 			{VIPS_REGION_SHRINK_MAX, "VIPS_REGION_SHRINK_MAX", "max"},
 			{VIPS_REGION_SHRINK_MIN, "VIPS_REGION_SHRINK_MIN", "min"},
+			{VIPS_REGION_SHRINK_NEAREST, "VIPS_REGION_SHRINK_NEAREST", "nearest"},
 			{VIPS_REGION_SHRINK_LAST, "VIPS_REGION_SHRINK_LAST", "last"},
 			{0, NULL, NULL}
 		};
diff --git a/libvips/iofuncs/header.c b/libvips/iofuncs/header.c
index 6a6347a3..dba1c767 100644
--- a/libvips/iofuncs/header.c
+++ b/libvips/iofuncs/header.c
@@ -36,6 +36,8 @@
  * 	- add vips_image_get_n_pages()
  * 20/6/19
  * 	- add vips_image_get/set_array_int()
+ * 31/1/19
+ * 	- lock for metadata changes
  */
 
 /*
@@ -130,6 +132,11 @@
  * these types, it can be copied between images efficiently.
  */
 
+/* Use in various small places where we need a mutex and it's not worth 
+ * making a private one.
+ */
+static GMutex *vips__meta_lock = NULL;
+
 /* We have to keep the gtype as a string, since we statically init this.
  */
 typedef struct _HeaderField {
@@ -934,10 +941,10 @@ meta_cp( VipsImage *dst, const VipsImage *src )
 		/* We lock with vips_image_set() to stop races in highly-
 		 * threaded applications.
 		 */
-		g_mutex_lock( vips__global_lock );
+		g_mutex_lock( vips__meta_lock );
 		vips_slist_map2( src->meta_traverse,
 			(VipsSListMap2Fn) meta_cp_field, dst, NULL );
-		g_mutex_unlock( vips__global_lock );
+		g_mutex_unlock( vips__meta_lock );
 	}
 
 	return( 0 );
@@ -1025,13 +1032,6 @@ vips_image_set( VipsImage *image, const char *name, GValue *value )
 	g_assert( name );
 	g_assert( value );
 
-        /* If this image is shared, block metadata changes.
-         */
-        if( G_OBJECT( image )->ref_count > 1 ) {
-                g_warning( "can't set metadata \"%s\" on shared image", name );
-                return;
-        }
-
 	meta_init( image );
 
 	/* We lock between modifying metadata and copying metadata between
@@ -1041,9 +1041,9 @@ vips_image_set( VipsImage *image, const char *name, GValue *value )
 	 * metadata copy on another -- this can lead to crashes in
 	 * highly-threaded applications.
 	 */
-	g_mutex_lock( vips__global_lock );
+	g_mutex_lock( vips__meta_lock );
 	(void) meta_new( image, name, value );
-	g_mutex_unlock( vips__global_lock );
+	g_mutex_unlock( vips__meta_lock );
 
 	/* If we're setting an EXIF data block, we need to automatically expand 
 	 * out all the tags. This will set things like xres/yres too.
@@ -1240,14 +1240,6 @@ vips_image_remove( VipsImage *image, const char *name )
 
 	result = FALSE;
 
-        /* If this image is shared, block metadata changes. 
-         */
-        if( G_OBJECT( image )->ref_count > 1 ) {
-                g_warning( "can't remove metadata \"%s\" on shared image", 
-			name );
-                return( result );
-        }
-
 	if( image->meta ) {
 		/* We lock between modifying metadata and copying metadata 
 		 * between images, see meta_cp().
@@ -1256,9 +1248,9 @@ vips_image_remove( VipsImage *image, const char *name )
 		 * racing with metadata copy on another -- this can lead to 
 		 * crashes in highly-threaded applications.
 		 */
-		g_mutex_lock( vips__global_lock );
+		g_mutex_lock( vips__meta_lock );
 		result = g_hash_table_remove( image->meta, name );
-		g_mutex_unlock( vips__global_lock );
+		g_mutex_unlock( vips__meta_lock );
 	}
 
 	return( result );
@@ -2027,3 +2019,12 @@ vips_image_get_history( VipsImage *image )
 
 	return( image->Hist ? image->Hist : "" );
 }
+
+/* Called during vips_init().
+ */
+void
+vips__meta_init( void )
+{
+	if( !vips__meta_lock ) 
+		vips__meta_lock = vips_g_mutex_new();
+}
diff --git a/libvips/iofuncs/init.c b/libvips/iofuncs/init.c
index bd5a90cc..d3a3310c 100644
--- a/libvips/iofuncs/init.c
+++ b/libvips/iofuncs/init.c
@@ -127,6 +127,8 @@ int vips__leak = 0;
 GQuark vips__image_pixels_quark = 0; 
 #endif /*DEBUG_LEAK*/
 
+static gint64 vips_pipe_read_limit = 1024 * 1024 * 1024;
+
 /**
  * vips_get_argv0:
  *
@@ -382,6 +384,7 @@ vips_init( const char *argv0 )
 
 	vips__threadpool_init();
 	vips__buffer_init();
+	vips__meta_init();
 
 	/* This does an unsynchronised static hash table init on first call --
 	 * we have to make sure we do this single-threaded. See: 
@@ -427,19 +430,20 @@ vips_init( const char *argv0 )
 	g_free( locale );
 	bind_textdomain_codeset( GETTEXT_PACKAGE, "UTF-8" );
 
-	/* Deprecated, this is just for compat.
-	 */
 	if( g_getenv( "VIPS_INFO" ) || 
 		g_getenv( "IM_INFO" ) ) 
 		vips_info_set( TRUE );
-
 	if( g_getenv( "VIPS_PROFILE" ) )
 		vips_profile_set( TRUE );
-
-	/* Default various settings from env.
-	 */
+	if( g_getenv( "VIPS_LEAK" ) )
+		vips_leak_set( TRUE );
 	if( g_getenv( "VIPS_TRACE" ) )
 		vips_cache_set_trace( TRUE );
+	if( g_getenv( "VIPS_PIPE_READ_LIMIT" ) ) 
+		vips_pipe_read_limit = 
+			g_ascii_strtoll( g_getenv( "VIPS_PIPE_READ_LIMIT" ),
+				NULL, 10 );
+	vips_pipe_read_limit_set( vips_pipe_read_limit );
 
 	/* Register base vips types.
 	 */
@@ -814,6 +818,9 @@ static GOptionEntry option_entries[] = {
 	{ "vips-version", 0, G_OPTION_FLAG_NO_ARG, 
 		G_OPTION_ARG_CALLBACK, (gpointer) &vips_lib_version_cb, 
 		N_( "print libvips version" ), NULL },
+	{ "vips-pipe-read-limit", 0, 0, 
+		G_OPTION_ARG_INT64, (gpointer) &vips_pipe_read_limit, 
+		N_( "read at most this many bytes from a pipe" ), NULL },
 	{ NULL }
 };
 
@@ -1192,8 +1199,8 @@ vips_version( int flag )
  * vips_leak_set:
  * @leak: turn leak checking on or off
  *
- * Turn on or off vips leak checking. See also --vips-leak and
- * vips_add_option_entries(). 
+ * Turn on or off vips leak checking. See also --vips-leak,
+ * vips_add_option_entries() and the `VIPS_LEAK` environment variable.
  *
  * You should call this very early in your program. 
  */
diff --git a/libvips/iofuncs/region.c b/libvips/iofuncs/region.c
index ab201ff5..50b4dc83 100644
--- a/libvips/iofuncs/region.c
+++ b/libvips/iofuncs/region.c
@@ -1235,6 +1235,8 @@ vips_region_shrink_uncoded_mean( VipsRegion *from,
  * IS stable with respect to the initial arrangement of input values
  */
 #define SHRINK_TYPE_MEDIAN( TYPE ) { \
+	int ls = VIPS_REGION_LSKIP( from ); \
+	\
 	for( x = 0; x < target->width; x++ ) { \
 		TYPE *tp = (TYPE *) p; \
 		TYPE *tp1 = (TYPE *) (p + ls); \
@@ -1265,6 +1267,8 @@ vips_region_shrink_uncoded_mean( VipsRegion *from,
  * IS stable with respect to the initial arrangement of input values
  */
 #define SHRINK_TYPE_MODE( TYPE ) { \
+	int ls = VIPS_REGION_LSKIP( from ); \
+	\
 	for( x = 0; x < target->width; x++ ) { \
 		TYPE *tp = (TYPE *) p; \
 		TYPE *tp1 = (TYPE *) (p + ls); \
@@ -1283,14 +1287,14 @@ vips_region_shrink_uncoded_mean( VipsRegion *from,
         		tq[z] = v[index]; \
 		} \
 		\
-		/* Move on two pels in input. \
-		 */ \
 		p += ps << 1; \
 		q += ps; \
 	} \
 }
 
 #define SHRINK_TYPE_MAX( TYPE ) { \
+	int ls = VIPS_REGION_LSKIP( from ); \
+	\
 	for( x = 0; x < target->width; x++ ) { \
 		TYPE *tp = (TYPE *) p; \
 		TYPE *tp1 = (TYPE *) (p + ls); \
@@ -1303,14 +1307,14 @@ vips_region_shrink_uncoded_mean( VipsRegion *from,
 				); \
 		} \
 		\
-		/* Move on two pels in input. \
-		 */ \
 		p += ps << 1; \
 		q += ps; \
 	} \
 }
 
 #define SHRINK_TYPE_MIN( TYPE ) { \
+	int ls = VIPS_REGION_LSKIP( from ); \
+	\
 	for( x = 0; x < target->width; x++ ) { \
 		TYPE *tp = (TYPE *) p; \
 		TYPE *tp1 = (TYPE *) (p + ls); \
@@ -1323,8 +1327,19 @@ vips_region_shrink_uncoded_mean( VipsRegion *from,
 				); \
 		} \
 		\
-		/* Move on two pels in input. \
-		 */ \
+		p += ps << 1; \
+		q += ps; \
+	} \
+}
+
+#define SHRINK_TYPE_NEAREST( TYPE ) { \
+	for( x = 0; x < target->width; x++ ) { \
+		TYPE *tp = (TYPE *) p; \
+		TYPE *tq = (TYPE *) q; \
+		\
+		for( z = 0; z < nb; z++ ) \
+        		tq[z] = tp[z]; \
+		\
 		p += ps << 1; \
 		q += ps; \
 	} \
@@ -1335,7 +1350,6 @@ static void \
 vips_region_shrink_uncoded_ ## OP( VipsRegion *from, \
 	VipsRegion *to, const VipsRect *target ) \
 { \
-	int ls = VIPS_REGION_LSKIP( from ); \
 	int ps = VIPS_IMAGE_SIZEOF_PEL( from->im ); \
 	int nb = from->im->Bands; \
  	\
@@ -1377,6 +1391,7 @@ VIPS_REGION_SHRINK( MAX );
 VIPS_REGION_SHRINK( MIN );
 VIPS_REGION_SHRINK( MODE );
 VIPS_REGION_SHRINK( MEDIAN );
+VIPS_REGION_SHRINK( NEAREST );
 
 /* Generate area @target in @to using pixels in @from. Non-complex.
  */
@@ -1405,6 +1420,10 @@ vips_region_shrink_uncoded( VipsRegion *from,
 			vips_region_shrink_uncoded_MIN( from, to, target );
 			break;
 
+		case VIPS_REGION_SHRINK_NEAREST:
+			vips_region_shrink_uncoded_NEAREST( from, to, target );
+			break;
+
 		default:
 			g_assert_not_reached();
 	}
diff --git a/libvips/iofuncs/source.c b/libvips/iofuncs/source.c
index 3c286007..af482d11 100644
--- a/libvips/iofuncs/source.c
+++ b/libvips/iofuncs/source.c
@@ -1,7 +1,10 @@
 /* A byte source/sink .. it can be a pipe, file descriptor, memory area, 
  * socket, node.js stream, etc.
  * 
- * J.Cupitt, 19/6/14
+ * 19/6/14
+ *
+ * 3/2/20
+ * 	- add vips_pipe_read_limit_set()
  */
 
 /*
@@ -84,10 +87,40 @@
 #define MODE_READWRITE BINARYIZE (O_RDWR)
 #define MODE_WRITE BINARYIZE (O_WRONLY | O_CREAT | O_TRUNC)
 
+/* -1 on a pipe isn't actually unbounded. Have a limit to prevent
+ * huge sources accidentally filling memory.
+ *
+ * This can be configured with vips_pipe_read_limit_set().
+ */
+static gint64 vips__pipe_read_limit = 1024 * 1024 * 1024;
+
+/**
+ * vips_pipe_read_limit_set:
+ * @limit: maximum number of bytes to buffer from a pipe
+ *
+ * If a source does not support mmap or seek and the source is
+ * used with a loader that can only work from memory, then the data will be
+ * automatically read into memory to EOF before the loader starts. This can
+ * produce high memory use if the descriptor represents a large object.
+ *
+ * Use vips_pipe_read_limit_set() to limit the size of object that
+ * will be read in this way. The default is 1GB. 
+ *
+ * Set a value of -1 to mean no limit.
+ *
+ * See also: `--vips-pipe-read-limit` and the environment variable 
+ * `VIPS_PIPE_READ_LIMIT`.
+ */
+void
+vips_pipe_read_limit_set( gint64 limit )
+{
+	vips__pipe_read_limit = limit;
+}
+
 G_DEFINE_TYPE( VipsSource, vips_source, VIPS_TYPE_CONNECTION );
 
 /* We can't test for seekability or length during _build, since the read and 
- * seek signal handlers may not have been connected yet. Instead, we test 
+ * seek signal handlers might not have been connected yet. Instead, we test 
  * when we first need to know.
  */
 static int
@@ -184,6 +217,9 @@ vips_source_sanity( VipsSource *source )
 		g_assert( source->length == -1 );
 	}
 	else {
+		/* Something like a seekable file.
+		 */
+
 		/* After we're done with the header, the sniff buffer should
 		 * be gone.
 		 */
@@ -377,6 +413,14 @@ vips_source_new_from_descriptor( int descriptor )
  *
  * Create an source attached to a file.
  *
+ * If this descriptor does not support mmap and the source is
+ * used with a loader that can only work from memory, then the data will be
+ * automatically read into memory to EOF before the loader starts. This can
+ * produce high memory use if the descriptor represents a large object.
+ *
+ * Use vips_pipe_read_limit_set() to limit the size of object that
+ * will be read in this way. The default is 1GB.
+ *
  * Returns: a new source.
  */
 VipsSource *
@@ -715,19 +759,14 @@ vips_source_read( VipsSource *source, void *buffer, size_t length )
 	return( total_read );
 }
 
-/* -1 on a pipe isn't actually unbounded. Have a limit to prevent
- * huge sources accidentally filling memory.
- *
- * 1gb. Why not.
- */
-static const int vips_pipe_read_limit = 1024 * 1024 * 1024;
-
 /* Read to a position. -1 means read to end of source. Does not change 
  * read_position.
  */
 static int
 vips_source_pipe_read_to_position( VipsSource *source, gint64 target )
 {
+	const char *nick = vips_connection_nick( VIPS_CONNECTION( source ) );
+
 	gint64 old_read_position;
 	unsigned char buffer[4096];
 
@@ -742,7 +781,7 @@ vips_source_pipe_read_to_position( VipsSource *source, gint64 target )
 		(target < 0 ||
 			(source->length != -1 && 
 			 target > source->length)) ) {
-		vips_error( vips_connection_nick( VIPS_CONNECTION( source ) ), 
+		vips_error( nick, 
 			_( "bad read to %" G_GINT64_FORMAT ), target );
 		return( -1 );
 	}
@@ -760,9 +799,9 @@ vips_source_pipe_read_to_position( VipsSource *source, gint64 target )
 			break;
 
 		if( target == -1 &&
-			source->read_position > vips_pipe_read_limit ) {
-			vips_error( vips_connection_nick( VIPS_CONNECTION( source ) ), 
-				"%s", _( "pipe too long" ) );
+			vips__pipe_read_limit != -1 &&
+			source->read_position > vips__pipe_read_limit ) {
+			vips_error( nick, "%s", _( "pipe too long" ) );
 			return( -1 );
 		}
 	}
@@ -1013,6 +1052,7 @@ vips_source_map_blob( VipsSource *source )
 gint64
 vips_source_seek( VipsSource *source, gint64 offset, int whence )
 {
+	const char *nick = vips_connection_nick( VIPS_CONNECTION( source ) );
 	VipsSourceClass *class = VIPS_SOURCE_GET_CLASS( source );
 
 	gint64 new_pos;
@@ -1039,8 +1079,7 @@ vips_source_seek( VipsSource *source, gint64 offset, int whence )
 			break;
 
 		default:
-			vips_error( vips_connection_nick( VIPS_CONNECTION( source ) ), 
-				"%s", _( "bad 'whence'" ) );
+			vips_error( nick, "%s", _( "bad 'whence'" ) );
 			return( -1 );
 		}
 	}
@@ -1066,8 +1105,7 @@ vips_source_seek( VipsSource *source, gint64 offset, int whence )
 			break;
 
 		default:
-			vips_error( vips_connection_nick( VIPS_CONNECTION( source ) ), 
-				"%s", _( "bad 'whence'" ) );
+			vips_error( nick, "%s", _( "bad 'whence'" ) );
 			return( -1 );
 		}
 	}
@@ -1081,7 +1119,7 @@ vips_source_seek( VipsSource *source, gint64 offset, int whence )
 	if( new_pos < 0 ||
 		(source->length != -1 && 
 		 new_pos > source->length) ) {
-		vips_error( vips_connection_nick( VIPS_CONNECTION( source ) ), 
+		vips_error( nick, 
 			_( "bad seek to %" G_GINT64_FORMAT ), new_pos );
                 return( -1 );
 	}
diff --git a/test/test-suite/helpers/helpers.py b/test/test-suite/helpers/helpers.py
index 68343d00..c493d55e 100644
--- a/test/test-suite/helpers/helpers.py
+++ b/test/test-suite/helpers/helpers.py
@@ -27,6 +27,11 @@ SVG_FILE = os.path.join(IMAGES, "logo.svg")
 SVGZ_FILE = os.path.join(IMAGES, "logo.svgz")
 SVG_GZ_FILE = os.path.join(IMAGES, "logo.svg.gz")
 GIF_ANIM_FILE = os.path.join(IMAGES, "cogs.gif")
+GIF_ANIM_EXPECTED_PNG_FILE = os.path.join(IMAGES, "cogs.png")
+GIF_ANIM_DISPOSE_BACKGROUND_FILE = os.path.join(IMAGES, "dispose-background.gif")
+GIF_ANIM_DISPOSE_BACKGROUND_EXPECTED_PNG_FILE = os.path.join(IMAGES, "dispose-background.png")
+GIF_ANIM_DISPOSE_PREVIOUS_FILE = os.path.join(IMAGES, "dispose-previous.gif")
+GIF_ANIM_DISPOSE_PREVIOUS_EXPECTED_PNG_FILE = os.path.join(IMAGES, "dispose-previous.png")
 DICOM_FILE = os.path.join(IMAGES, "dicom_test_image.dcm")
 BMP_FILE = os.path.join(IMAGES, "MARBLES.BMP")
 NIFTI_FILE = os.path.join(IMAGES, "avg152T1_LR_nifti.nii.gz")
diff --git a/test/test-suite/images/cogs.png b/test/test-suite/images/cogs.png
new file mode 100644
index 00000000..2256a6a8
Binary files /dev/null and b/test/test-suite/images/cogs.png differ
diff --git a/test/test-suite/images/dispose-background.gif b/test/test-suite/images/dispose-background.gif
new file mode 100644
index 00000000..dfdac192
Binary files /dev/null and b/test/test-suite/images/dispose-background.gif differ
diff --git a/test/test-suite/images/dispose-background.png b/test/test-suite/images/dispose-background.png
new file mode 100644
index 00000000..0e29eb52
Binary files /dev/null and b/test/test-suite/images/dispose-background.png differ
diff --git a/test/test-suite/images/dispose-previous.gif b/test/test-suite/images/dispose-previous.gif
new file mode 100644
index 00000000..c4b5b0e6
Binary files /dev/null and b/test/test-suite/images/dispose-previous.gif differ
diff --git a/test/test-suite/images/dispose-previous.png b/test/test-suite/images/dispose-previous.png
new file mode 100644
index 00000000..c2231022
Binary files /dev/null and b/test/test-suite/images/dispose-previous.png differ
diff --git a/test/test-suite/test_foreign.py b/test/test-suite/test_foreign.py
index 4c18af71..cb4b4b21 100644
--- a/test/test-suite/test_foreign.py
+++ b/test/test-suite/test_foreign.py
@@ -1,5 +1,5 @@
 # vim: set fileencoding=utf-8 :
-
+import filecmp
 import sys
 import os
 import shutil
@@ -12,6 +12,9 @@ from helpers import \
     ANALYZE_FILE, GIF_FILE, WEBP_FILE, EXR_FILE, FITS_FILE, OPENSLIDE_FILE, \
     PDF_FILE, SVG_FILE, SVGZ_FILE, SVG_GZ_FILE, GIF_ANIM_FILE, DICOM_FILE, \
     BMP_FILE, NIFTI_FILE, ICO_FILE, HEIC_FILE, TRUNCATED_FILE, \
+    GIF_ANIM_EXPECTED_PNG_FILE, \
+    GIF_ANIM_DISPOSE_BACKGROUND_FILE, GIF_ANIM_DISPOSE_BACKGROUND_EXPECTED_PNG_FILE, \
+    GIF_ANIM_DISPOSE_PREVIOUS_FILE, GIF_ANIM_DISPOSE_PREVIOUS_EXPECTED_PNG_FILE, \
     temp_filename, assert_almost_equal_objects, have, skip_if_no
 
 
@@ -419,11 +422,14 @@ class TestForeign:
         assert a.height == b.height
         assert a.avg() == b.avg()
 
-        # region-shrink added in 8.7
         x = pyvips.Image.new_from_file(TIF_FILE)
         buf = x.tiffsave_buffer(tile=True, pyramid=True, region_shrink="mean")
         buf = x.tiffsave_buffer(tile=True, pyramid=True, region_shrink="mode")
         buf = x.tiffsave_buffer(tile=True, pyramid=True, region_shrink="median")
+        buf = x.tiffsave_buffer(tile=True, pyramid=True, region_shrink="max")
+        buf = x.tiffsave_buffer(tile=True, pyramid=True, region_shrink="min")
+        buf = x.tiffsave_buffer(tile=True, pyramid=True,
+                                region_shrink="nearest")
 
     @skip_if_no("magickload")
     def test_magickload(self):
@@ -703,6 +709,38 @@ class TestForeign:
             x2 = pyvips.Image.new_from_file(GIF_ANIM_FILE, page=1, n=-1)
             assert x2.height == 4 * x1.height
 
+            animation = pyvips.Image.new_from_file(GIF_ANIM_FILE, n=-1)
+            filename = temp_filename(self.tempdir, '.png')
+            animation.write_to_file(filename)
+            # Uncomment to see output file
+            # animation.write_to_file('cogs.png')
+
+            assert filecmp.cmp(GIF_ANIM_EXPECTED_PNG_FILE, filename, shallow=False)
+
+    @skip_if_no("gifload")
+    def test_gifload_animation_dispose_background(self):
+        animation = pyvips.Image.new_from_file(GIF_ANIM_DISPOSE_BACKGROUND_FILE, n=-1)
+
+        filename = temp_filename(self.tempdir, '.png')
+        animation.write_to_file(filename)
+
+        # Uncomment to see output file
+        # animation.write_to_file('dispose-background.png')
+
+        assert filecmp.cmp(GIF_ANIM_DISPOSE_BACKGROUND_EXPECTED_PNG_FILE, filename, shallow=False)
+
+    @skip_if_no("gifload")
+    def test_gifload_animation_dispose_previous(self):
+        animation = pyvips.Image.new_from_file(GIF_ANIM_DISPOSE_PREVIOUS_FILE, n=-1)
+
+        filename = temp_filename(self.tempdir, '.png')
+        animation.write_to_file(filename)
+
+        # Uncomment to see output file
+        # animation.write_to_file('dispose-previous.png')
+
+        assert filecmp.cmp(GIF_ANIM_DISPOSE_PREVIOUS_EXPECTED_PNG_FILE, filename, shallow=False)
+
     @skip_if_no("svgload")
     def test_svgload(self):
         def svg_valid(im):
diff --git a/tools/vipsthumbnail.c b/tools/vipsthumbnail.c
index 961d447d..3e9c37cc 100644
--- a/tools/vipsthumbnail.c
+++ b/tools/vipsthumbnail.c
@@ -96,6 +96,10 @@
  * 	- add --intent
  * 23/10/17
  * 	- --size Nx didn't work, argh ... thanks jrochkind 
+ * 3/2/20
+ * 	- add --no-rotate
+ * 	- add --import-profile / --export-profile names
+ * 	- back to -o for output
  */
 
 #ifdef HAVE_CONFIG_H
@@ -127,8 +131,8 @@ static char *import_profile = NULL;
 static gboolean delete_profile = FALSE;
 static gboolean linear_processing = FALSE;
 static gboolean crop_image = FALSE;
+static gboolean no_rotate_image = FALSE;
 static char *smartcrop_image = NULL;
-static gboolean rotate_image = FALSE;
 static char *thumbnail_intent = NULL;
 
 /* Deprecated and unused.
@@ -138,25 +142,22 @@ static gboolean nodelete_profile = FALSE;
 static gboolean verbose = FALSE;
 static char *convolution_mask = NULL;
 static char *interpolator = NULL;
+static gboolean rotate_image = FALSE;
 
 static GOptionEntry options[] = {
 	{ "size", 's', 0, 
 		G_OPTION_ARG_STRING, &thumbnail_size, 
 		N_( "shrink to SIZE or to WIDTHxHEIGHT" ), 
 		N_( "SIZE" ) },
-	{ "output", 'o', G_OPTION_FLAG_HIDDEN, 
+	{ "output", 'o', 0, 
 		G_OPTION_ARG_STRING, &output_format, 
-		N_( "set output to FORMAT" ), 
+		N_( "output to FORMAT" ), 
 		N_( "FORMAT" ) },
-	{ "format", 'f', 0, 
-		G_OPTION_ARG_STRING, &output_format, 
-		N_( "set output format string to FORMAT" ), 
-		N_( "FORMAT" ) },
-	{ "eprofile", 'e', 0, 
+	{ "export-profile", 'e', 0, 
 		G_OPTION_ARG_FILENAME, &export_profile, 
 		N_( "export with PROFILE" ), 
 		N_( "PROFILE" ) },
-	{ "iprofile", 'i', 0, 
+	{ "import-profile", 'i', 0, 
 		G_OPTION_ARG_FILENAME, &import_profile, 
 		N_( "import untagged images with PROFILE" ), 
 		N_( "PROFILE" ) },
@@ -171,13 +172,28 @@ static GOptionEntry options[] = {
 		G_OPTION_ARG_STRING, &thumbnail_intent, 
 		N_( "ICC transform with INTENT" ), 
 		N_( "INTENT" ) },
-	{ "rotate", 't', 0, 
-		G_OPTION_ARG_NONE, &rotate_image, 
-		N_( "auto-rotate" ), NULL },
 	{ "delete", 'd', 0, 
 		G_OPTION_ARG_NONE, &delete_profile, 
 		N_( "delete profile from exported image" ), NULL },
+	{ "no-rotate", 0, 0, 
+		G_OPTION_ARG_NONE, &no_rotate_image, 
+		N_( "don't auto-rotate" ), NULL },
 
+	{ "format", 'f', G_OPTION_FLAG_HIDDEN, 
+		G_OPTION_ARG_STRING, &output_format, 
+		N_( "set output format string to FORMAT" ), 
+		N_( "FORMAT" ) },
+	{ "eprofile", 0, G_OPTION_FLAG_HIDDEN, 
+		G_OPTION_ARG_FILENAME, &export_profile, 
+		N_( "export with PROFILE" ), 
+		N_( "PROFILE" ) },
+	{ "iprofile", 0, G_OPTION_FLAG_HIDDEN, 
+		G_OPTION_ARG_FILENAME, &import_profile, 
+		N_( "import untagged images with PROFILE" ), 
+		N_( "PROFILE" ) },
+	{ "rotate", 't', G_OPTION_FLAG_HIDDEN, 
+		G_OPTION_ARG_NONE, &rotate_image, 
+		N_( "(deprecated, does nothing)" ), NULL },
 	{ "crop", 'c', G_OPTION_FLAG_HIDDEN, 
 		G_OPTION_ARG_NONE, &crop_image, 
 		N_( "(deprecated, crop exactly to SIZE)" ), NULL },
@@ -280,11 +296,11 @@ thumbnail_process( VipsObject *process, const char *filename )
 	if( vips_thumbnail( filename, &image, thumbnail_width, 
 		"height", thumbnail_height, 
 		"size", size_restriction, 
-		"auto_rotate", rotate_image, 
+		"no-rotate", no_rotate_image, 
 		"crop", interesting, 
 		"linear", linear_processing, 
-		"import_profile", import_profile, 
-		"export_profile", export_profile, 
+		"import-profile", import_profile, 
+		"export-profile", export_profile, 
 		"intent", intent, 
 		NULL ) )
 		return( -1 );