From c46f4b15e02741b727a197780e3d58011572bb23 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Fri, 26 Jan 2018 15:36:43 +0000
Subject: [PATCH] dzsave to szi sets extension correctly

see https://github.com/jcupitt/libvips/issues/852
---
 ChangeLog                |  1 +
 libvips/foreign/dzsave.c | 21 +++++++++++++++++----
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index cc079a8d..9a79527e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,6 @@
 23/12/17 started 8.7.0
 - add magicksave, save image with libMagick [dlemstra]
+- dzsave to szi sets suffix correctly [martinweihrauch]
 
 5/1/18 started 8.6.2
 - vips_sink_screen() keeps a ref to the input image ... stops a rare race
diff --git a/libvips/foreign/dzsave.c b/libvips/foreign/dzsave.c
index 44d3ed82..98f4c014 100644
--- a/libvips/foreign/dzsave.c
+++ b/libvips/foreign/dzsave.c
@@ -527,6 +527,11 @@ struct _VipsForeignSaveDz {
 	 */
 	VipsPel *ink;
 
+	/* TRUE if we are writing a .szi file. These are zips with a few 
+	 * extra files inside. 
+	 */
+	gboolean write_szi;
+
 };
 
 typedef VipsForeignSaveClass VipsForeignSaveDzClass;
@@ -1857,9 +1862,11 @@ vips_foreign_save_dz_build( VipsObject *object )
 		/* Output to a file or memory?
 		 */
 		if( dz->dirname ) { 
-			vips_snprintf( name, VIPS_PATH_MAX, "%s/%s.zip", 
-				dz->dirname, dz->basename ); 
-			if( !(dz->out = gsf_output_stdio_new( name, &error )) ) {
+			const char *suffix = dz->write_szi ? "szi" : "zip"; 
+			vips_snprintf( name, VIPS_PATH_MAX, "%s/%s.%s", 
+				dz->dirname, dz->basename, suffix ); 
+			if( !(dz->out = 
+				gsf_output_stdio_new( name, &error )) ) {
 				vips_g_error( &error );
 				return( -1 );
 			}
@@ -2176,11 +2183,17 @@ vips_foreign_save_dz_file_build( VipsObject *object )
 	 * container.
 	 */
 	if( (p = strrchr( dz->basename, '.' )) ) {
-		if( !vips_object_argument_isset( object, "container" ) ) 
+		if( !vips_object_argument_isset( object, "container" ) ) {
 			if( strcasecmp( p + 1, "zip" ) == 0 ||
 				strcasecmp( p + 1, "szi" ) == 0 ) 
 				dz->container = VIPS_FOREIGN_DZ_CONTAINER_ZIP;
 
+			/* Note we are building a .szi object.
+			 */
+			if( strcasecmp( p + 1, "szi" ) == 0 ) 
+				dz->write_szi = TRUE;
+		}
+
 		/* Remove any legal suffix. We don't remove all suffixes
 		 * since we might be writing to a dirname with a dot in.
 		 */