always copy before exif_update

During write, we often call vips__exif_update(). This updates the exif
block from the other image metadata prior to save.

Always copy the image before calling this.

See lovell/sharp#1986

ChangeLog

@@ -25,6 +25,7 @@
 - fix use of resolution-unit metadata on tiff save [kayarre]
 - support TIFF CIELAB images with alpha [angelmixu]
 - support TIFF with premultiplied alpha in any band 
+- block metadata changes on shared images [pvdz]
 
 17/9/19 started 8.8.4
 - improve compatibility with older imagemagick versions

libvips/foreign/heifsave.c

@@ -73,6 +73,11 @@ typedef struct _VipsForeignSaveHeif {
 	 */
 	VipsForeignHeifCompression compression;
 
+	/* The image we save. This is a copy of save->ready since we need to
+	 * be able to update the metadata.
+	 */
+	VipsImage *image;
+
 	int page_width;
 	int page_height;
 	int n_pages;
@@ -107,6 +112,7 @@ vips_foreign_save_heif_dispose( GObject *gobject )
 {
 	VipsForeignSaveHeif *heif = (VipsForeignSaveHeif *) gobject;
 
+	VIPS_UNREF( heif->image );
 	VIPS_FREEF( heif_image_release, heif->img );
 	VIPS_FREEF( heif_image_handle_release, heif->handle );
 	VIPS_FREEF( heif_encoder_release, heif->encoder );
@@ -134,13 +140,12 @@ static int
 vips_foreign_save_heif_write_metadata( VipsForeignSaveHeif *heif )
 {
 #ifdef HAVE_HEIF_CONTEXT_ADD_EXIF_METADATA
-	VipsForeignSave *save = (VipsForeignSave *) heif;
 
 	int i;
 	struct heif_error error;
 
 	for( i = 0; i < VIPS_NUMBER( libheif_metadata ); i++ )  
-		if( vips_image_get_typeof( save->ready, 
+		if( vips_image_get_typeof( heif->image, 
 			libheif_metadata[i].name ) ) {
 			const void *data;
 			size_t length;
@@ -150,7 +155,7 @@ vips_foreign_save_heif_write_metadata( VipsForeignSaveHeif *heif )
 				libheif_metadata[i].name ); 
 #endif /*DEBUG*/
 
-			if( vips_image_get_blob( save->ready, 
+			if( vips_image_get_blob( heif->image, 
 				VIPS_META_EXIF_NAME, &data, &length ) )
 				return( -1 );
 
@@ -176,15 +181,15 @@ vips_foreign_save_heif_write_page( VipsForeignSaveHeif *heif, int page )
 
 #ifdef HAVE_HEIF_COLOR_PROFILE
 	if( !save->strip &&
-		vips_image_get_typeof( save->ready, VIPS_META_ICC_NAME ) ) {
+		vips_image_get_typeof( heif->image, VIPS_META_ICC_NAME ) ) {
 		const void *data;
 		size_t length;
 
 #ifdef DEBUG
 		printf( "attaching profile ..\n" ); 
 #endif /*DEBUG*/
 
-		if( vips_image_get_blob( save->ready, 
+		if( vips_image_get_blob( heif->image, 
 			VIPS_META_ICC_NAME, &data, &length ) )
 			return( -1 );
 
@@ -201,7 +206,7 @@ vips_foreign_save_heif_write_page( VipsForeignSaveHeif *heif, int page )
 
 #ifdef HAVE_HEIF_ENCODING_OPTIONS_ALLOC
 	options = heif_encoding_options_alloc();
-	if( vips_image_hasalpha( save->ready ) )
+	if( vips_image_hasalpha( heif->image ) )
 		options->save_alpha_channel = 1;
 #else /*!HAVE_HEIF_ENCODING_OPTIONS_ALLOC*/
 	options = NULL;
@@ -223,10 +228,10 @@ vips_foreign_save_heif_write_page( VipsForeignSaveHeif *heif, int page )
 	}
 
 #ifdef HAVE_HEIF_CONTEXT_SET_PRIMARY_IMAGE
-	if( vips_image_get_typeof( save->ready, "heif-primary" ) ) { 
+	if( vips_image_get_typeof( heif->image, "heif-primary" ) ) { 
 		int primary;
 
-		if( vips_image_get_int( save->ready, 
+		if( vips_image_get_int( heif->image, 
 			"heif-primary", &primary ) ) 
 			return( -1 ); 	
 
@@ -299,6 +304,12 @@ vips_foreign_save_heif_build( VipsObject *object )
 		build( object ) )
 		return( -1 );
 
+	/* We must copy the input image since we will be updating the
+	 * metadata when we write the exif.
+	 */
+	if( vips_copy( save->ready, &heif->image, NULL ) ) 
+		return( -1 );
+
 	error = heif_context_get_encoder_for_format( heif->ctx, 
 		(enum heif_compression_format) heif->compression, 
 		&heif->encoder );
@@ -328,16 +339,16 @@ vips_foreign_save_heif_build( VipsObject *object )
 	 * heif_encoder_list_parameters().
 	 */
 
-	heif->page_width = save->ready->Xsize;
-	heif->page_height = vips_image_get_page_height( save->ready );
-	heif->n_pages = save->ready->Ysize / heif->page_height;
+	heif->page_width = heif->image->Xsize;
+	heif->page_height = vips_image_get_page_height( heif->image );
+	heif->n_pages = heif->image->Ysize / heif->page_height;
 
 	/* Make a heif image the size of a page. We send sink_disc() output 
 	 * here and write a frame each time it fills.
 	 */
 	error = heif_image_create( heif->page_width, heif->page_height, 
 		heif_colorspace_RGB, 
-		vips_image_hasalpha( save->ready ) ?
+		vips_image_hasalpha( heif->image ) ?
 			heif_chroma_interleaved_RGBA : 
 			heif_chroma_interleaved_RGB,
 		&heif->img );
@@ -348,7 +359,7 @@ vips_foreign_save_heif_build( VipsObject *object )
 
 	error = heif_image_add_plane( heif->img, heif_channel_interleaved, 
 		heif->page_width, heif->page_height, 
-		vips_image_hasalpha( save->ready ) ? 32 : 24 );
+		vips_image_hasalpha( heif->image ) ? 32 : 24 );
 	if( error.code ) {
 		vips__heif_error( &error );
 		return( -1 );
@@ -359,13 +370,13 @@ vips_foreign_save_heif_build( VipsObject *object )
 
 	/* Just do this once, so we don't rebuild exif on every page.
 	 */
-	if( vips_image_get_typeof( save->ready, VIPS_META_EXIF_NAME ) ) 
-		if( vips__exif_update( save->ready ) )
+	if( vips_image_get_typeof( heif->image, VIPS_META_EXIF_NAME ) ) 
+		if( vips__exif_update( heif->image ) )
 			return( -1 );
 
 	/* Write data. 
 	 */
-	if( vips_sink_disc( save->ready, 
+	if( vips_sink_disc( heif->image, 
 		vips_foreign_save_heif_write_block, heif ) )
 		return( -1 );
 

libvips/foreign/vips2jpeg.c

@@ -211,6 +211,7 @@ write_destroy( Write *write )
 	jpeg_destroy_compress( &write->cinfo );
 	VIPS_FREE( write->row_pointer );
 	VIPS_UNREF( write->inverted );
+	VIPS_UNREF( write->in );
 
 	g_free( write );
 }
@@ -223,7 +224,7 @@ write_new( VipsImage *in )
 	if( !(write = g_new0( Write, 1 )) )
 		return( NULL );
 
-	write->in = in;
+	write->in = NULL;
 	write->row_pointer = NULL;
         write->cinfo.err = jpeg_std_error( &write->eman.pub );
 	write->cinfo.dest = NULL;
@@ -232,6 +233,14 @@ write_new( VipsImage *in )
 	write->eman.fp = NULL;
 	write->inverted = NULL;
 
+	/* We must copy the input image since we will be updating the
+	 * metadata when we write the exif.
+	 */
+	if( vips_copy( in, &write->in, NULL ) ) {
+		write_destroy( write );
+		return( NULL );
+	}
+
         return( write );
 }
 

libvips/foreign/vips2webp.c

@@ -137,6 +137,7 @@ vips_webp_write_unset( VipsWebPWrite *write )
 	WebPMemoryWriterClear( &write->memory_writer );
 	VIPS_FREEF( WebPAnimEncoderDelete, write->enc );
 	VIPS_FREEF( WebPMuxDelete, write->mux );
+	VIPS_UNREF( write->image );
 }
 
 static int
@@ -147,7 +148,7 @@ vips_webp_write_init( VipsWebPWrite *write, VipsImage *image,
 	gboolean min_size, int kmin, int kmax,
 	gboolean strip )
 {
-	write->image = image;
+	write->image = NULL;
 	write->Q = Q;
 	write->lossless = lossless;
 	write->preset = preset;
@@ -163,6 +164,14 @@ vips_webp_write_init( VipsWebPWrite *write, VipsImage *image,
 	write->enc = NULL;
 	write->mux = NULL;
 
+	/* We must copy the input image since we will be updating the
+	 * metadata when we write the exif.
+	 */
+	if( vips_copy( image, &write->image, NULL ) ) {
+		vips_webp_write_unset( write );
+		return( -1 );
+	}
+
 	if( !WebPConfigInit( &write->config ) ) {
 		vips_webp_write_unset( write );
 		vips_error( "vips2webp",
@@ -390,14 +399,14 @@ write_webp_anim( VipsWebPWrite *write, VipsImage *image, int page_height )
 }
 
 static int
-write_webp( VipsWebPWrite *write, VipsImage *image )
+write_webp( VipsWebPWrite *write )
 {
-	int page_height = vips_image_get_page_height( image ); 
+	int page_height = vips_image_get_page_height( write->image ); 
 
-	if( page_height < image->Ysize )
-		return( write_webp_anim( write, image, page_height ) );
+	if( page_height < write->image->Ysize )
+		return( write_webp_anim( write, write->image, page_height ) );
 	else
-		return( write_webp_single( write, image ) );
+		return( write_webp_single( write, write->image ) );
 }
 
 static void
@@ -437,19 +446,19 @@ vips_webp_set_chunk( VipsWebPWrite *write,
 }
 
 static int 
-vips_webp_add_chunks( VipsWebPWrite *write, VipsImage *image )
+vips_webp_add_chunks( VipsWebPWrite *write )
 {
 	int i;
 
 	for( i = 0; i < vips__n_webp_names; i++ ) { 
 		const char *vips_name = vips__webp_names[i].vips;
 		const char *webp_name = vips__webp_names[i].webp;
 
-		if( vips_image_get_typeof( image, vips_name ) ) {
+		if( vips_image_get_typeof( write->image, vips_name ) ) {
 			const void *data;
 			size_t length;
 
-			if( vips_image_get_blob( image, 
+			if( vips_image_get_blob( write->image, 
 				vips_name, &data, &length ) ||
 				vips_webp_set_chunk( write, 
 					webp_name, data, length ) )
@@ -461,13 +470,13 @@ vips_webp_add_chunks( VipsWebPWrite *write, VipsImage *image )
 }
 
 static int 
-vips_webp_add_metadata( VipsWebPWrite *write, VipsImage *image, gboolean strip )
+vips_webp_add_metadata( VipsWebPWrite *write )
 {
 	WebPData data;
 
 	/* Rebuild the EXIF block, if any, ready for writing. 
 	 */
-	if( vips__exif_update( image ) )
+	if( vips__exif_update( write->image ) )
 		return( -1 ); 
 
 	data.bytes = write->memory_writer.mem;
@@ -480,19 +489,19 @@ vips_webp_add_metadata( VipsWebPWrite *write, VipsImage *image, gboolean strip )
 		return( -1 );
 	}
 
-	if( vips_image_get_typeof( image, "gif-loop" ) ) {
+	if( vips_image_get_typeof( write->image, "gif-loop" ) ) {
 		int gif_loop;
 
-		if( vips_image_get_int( image, "gif-loop", &gif_loop ) )
+		if( vips_image_get_int( write->image, "gif-loop", &gif_loop ) )
 			return( -1 );
 
 		vips_webp_set_count( write, gif_loop );
 	}
 
 	/* Add extra metadata.
 	 */
-	if( !strip &&
-		vips_webp_add_chunks( write, image ) ) 
+	if( !write->strip &&
+		vips_webp_add_chunks( write ) ) 
 		return( -1 );
 
 	if( WebPMuxAssemble( write->mux, &data ) != WEBP_MUX_OK ) {
@@ -524,12 +533,12 @@ vips__webp_write_stream( VipsImage *image, VipsStreamo *streamo,
 		alpha_q, reduction_effort, min_size, kmin, kmax, strip ) )
 		return( -1 );
 
-	if( write_webp( &write, image ) ) {
+	if( write_webp( &write ) ) {
 		vips_webp_write_unset( &write );
 		return( -1 );
 	}
 
-	if( vips_webp_add_metadata( &write, image, strip ) ) {
+	if( vips_webp_add_metadata( &write ) ) {
 		vips_webp_write_unset( &write );
 		return( -1 );
 	}

libvips/iofuncs/header.c

@@ -1023,7 +1023,7 @@ vips_image_set( VipsImage *image, const char *name, GValue *value )
         /* If this image is shared, block metadata changes. 
          */
         if( G_OBJECT( image )->ref_count > 1 ) {
-                g_info( "can't set metadata \"%s\" on shared image", name );
+                g_warning( "can't set metadata \"%s\" on shared image", name );
                 return;
         }
 
@@ -1223,7 +1223,8 @@ vips_image_remove( VipsImage *image, const char *name )
         /* If this image is shared, block metadata changes. 
          */
         if( G_OBJECT( image )->ref_count > 1 ) {
-                g_info( "can't remove metadata \"%s\" on shared image", name );
+                g_warning( "can't remove metadata \"%s\" on shared image", 
+			name );
                 return( FALSE );
         }