From d14e0d5c9790637c0b5310ed4298751b1ddb9dbb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tom=C3=A1=C5=A1=20Szabo?= <tomas.szabo@deftomat.com>
Date: Tue, 17 Dec 2019 07:28:28 +0100
Subject: [PATCH] feat: add normalized `loop` field

---
 libvips/foreign/gifload.c    |  9 ++++++++-
 libvips/foreign/magicksave.c | 17 ++++++++++++-----
 libvips/foreign/vips2webp.c  | 18 ++++++++++++++----
 libvips/foreign/webp2vips.c  | 10 +++++++++-
 4 files changed, 43 insertions(+), 11 deletions(-)

diff --git a/libvips/foreign/gifload.c b/libvips/foreign/gifload.c
index a34ed8bb..04e51f5e 100644
--- a/libvips/foreign/gifload.c
+++ b/libvips/foreign/gifload.c
@@ -590,7 +590,14 @@ vips_foreign_load_gif_set_header( VipsForeignLoadGif *gif, VipsImage *image )
 		vips_image_set_int( image,
 			VIPS_META_PAGE_HEIGHT, gif->file->SHeight );
 	vips_image_set_int( image, VIPS_META_N_PAGES, gif->n_pages );
-	vips_image_set_int( image, "gif-loop", gif->loop );
+	vips_image_set_int( image, "loop", gif->loop );
+
+	/* DEPRECATED "gif-loop"
+	 *
+	 * 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 );
 
 	if( gif->delays ) {
 		/* The deprecated gif-delay field is in centiseconds.
diff --git a/libvips/foreign/magicksave.c b/libvips/foreign/magicksave.c
index 5eee1a20..8e47f16b 100644
--- a/libvips/foreign/magicksave.c
+++ b/libvips/foreign/magicksave.c
@@ -163,13 +163,20 @@ vips_foreign_save_magick_next_image( VipsForeignSaveMagick *magick )
 	 * 	1 - don't write the netscape extension block
 	 * 	2 - loop once
 	 * 	3 - loop twice etc.
-	 *
-	 * We have the simple gif meaning, so we must add one unless it's
-	 * zero.
 	 */
-	if( vips_image_get_typeof( im, "gif-loop" ) &&
-		!vips_image_get_int( im, "gif-loop", &number ) )
+	if( vips_image_get_typeof( im, "loop" ) &&
+		!vips_image_get_int( im, "loop", &number ) ) {
 		image->iterations = (size_t) (number ? number : 0);
+	}
+	else {
+		/* DEPRECATED "gif-loop"
+		 *
+		 * We have the simple gif meaning, so we must add one unless it's zero.
+		 */
+		if( vips_image_get_typeof( im, "gif-loop" ) &&
+			!vips_image_get_int( im, "gif-loop", &number ) )
+			image->iterations = (size_t) (number ? number + 1 : 0);
+	}
 
 	if( vips_image_get_typeof( im, "gif-comment" ) &&
 		!vips_image_get_string( im, "gif-comment", &str ) )
diff --git a/libvips/foreign/vips2webp.c b/libvips/foreign/vips2webp.c
index a1dda939..ca0df25c 100644
--- a/libvips/foreign/vips2webp.c
+++ b/libvips/foreign/vips2webp.c
@@ -478,13 +478,23 @@ vips_webp_add_metadata( VipsWebPWrite *write, VipsImage *image, gboolean strip )
 		return( -1 );
 	}
 
-	if( vips_image_get_typeof( image, "gif-loop" ) ) {
-		int gif_loop;
+	if( vips_image_get_typeof( image, "loop" ) ) {
+		int loop;
 
-		if( vips_image_get_int( image, "gif-loop", &gif_loop ) )
+		if( vips_image_get_int( image, "loop", &loop ) )
 			return( -1 );
 
-		vips_webp_set_count( write, gif_loop );
+		vips_webp_set_count( write, loop );
+	}
+	/* DEPRECATED "gif-loop"
+	 */
+	else if ( vips_image_get_typeof( image, "gif-loop" ) ) {
+		int loop;
+
+		if( vips_image_get_int( image, "gif-loop", &loop ) )
+			return( -1 );
+
+		vips_webp_set_count( write, loop == 0 ? 0 : loop + 1 );
 	}
 
 	/* Add extra metadata.
diff --git a/libvips/foreign/webp2vips.c b/libvips/foreign/webp2vips.c
index 7e28015e..bf03555e 100644
--- a/libvips/foreign/webp2vips.c
+++ b/libvips/foreign/webp2vips.c
@@ -473,7 +473,15 @@ read_header( Read *read, VipsImage *out )
 		printf( "webp2vips: frame_count = %d\n", read->frame_count );
 #endif /*DEBUG*/
 
-		vips_image_set_int( out, "gif-loop", loop_count );
+		vips_image_set_int( out, "loop", loop_count );
+
+		/* DEPRECATED "gif-loop"
+		 *
+		 * Not the correct behavior as loop=1 became gif-loop=0
+		 * but we want to keep the old behavior untouched!
+		 */
+		vips_image_set_int( out, "gif-loop", loop_count == 0 ? 0 : loop_count - 1 );
+		
 		vips_image_set_int( out, 
 			VIPS_META_PAGE_HEIGHT, read->frame_height );