From 29e05dabaf0772bac57bad63b2e09ce1c9298c4b Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Thu, 8 Mar 2018 13:11:54 +0000
Subject: [PATCH] icc_import attaches the input profile if used

icc_import can take a fallback input profile in case the embedded one is
broken or missing. If we use the fallback profile, this change attaches
it to the output image.

This means that icc_import will always output an image with the icc
profile that was used to import it. This helps to make the behaviour of
`thumbnail` more consistent.

See https://github.com/jcupitt/libvips/issues/152
---
 ChangeLog                      |  1 +
 libvips/colour/icc_transform.c | 31 ++++++++++++++++++++++++++++++-
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 08aaab8c..282bd848 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -5,6 +5,7 @@
 - better rounding behaviour in convolution means we hit the vector path more
   often
 - fix a crash if a delayed load failed [gsharpsh00ter]
+- icc_import attaches the fallback profile if it used it
 
 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/colour/icc_transform.c b/libvips/colour/icc_transform.c
index 9345c66b..7b9d0d53 100644
--- a/libvips/colour/icc_transform.c
+++ b/libvips/colour/icc_transform.c
@@ -36,6 +36,8 @@
  * 	- remove lcms1 support, it was untested
  * 10/10/17
  * 	- more input profile sanity tests
+ * 8/3/18
+ * 	- attach fallback profile on import if we used it
  */
 
 /*
@@ -392,6 +394,10 @@ typedef struct _VipsIccImport {
 	gboolean embedded;
 	char *input_profile_filename;
 
+	/* Set if we ended up using the fallback input profile. 
+	 */
+	gboolean used_fallback;
+
 } VipsIccImport;
 
 typedef VipsIccClass VipsIccImportClass;
@@ -615,6 +621,7 @@ static int
 vips_icc_import_build( VipsObject *object )
 {
 	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( object ); 
+	VipsColour *colour = (VipsColour *) object;
 	VipsColourCode *code = (VipsColourCode *) object;
 	VipsIcc *icc = (VipsIcc *) object;
 	VipsIccImport *import = (VipsIccImport *) object;
@@ -637,9 +644,11 @@ vips_icc_import_build( VipsObject *object )
 
 	if( !icc->in_profile &&
 		code->in &&
-		import->input_profile_filename ) 
+		import->input_profile_filename ) {
 		icc->in_profile = vips_icc_load_profile_file( class->nickname,
 			code->in, import->input_profile_filename );
+	 	import->used_fallback = TRUE;
+	}
 
 	if( !icc->in_profile ) {
 		vips_error( class->nickname, "%s", _( "no input profile" ) ); 
@@ -661,6 +670,26 @@ vips_icc_import_build( VipsObject *object )
 	if( VIPS_OBJECT_CLASS( vips_icc_import_parent_class )->build( object ) )
 		return( -1 );
 
+	/* If we used the fallback profile, we need to attach it to the PCS
+	 * image since the PCS image needs to know about a route back to 
+	 * device space.
+	 *
+	 * In the same way, we don't remove the embedded input profile on
+	 * import.
+	 */
+	if( import->used_fallback ) {
+		char *data;
+		size_t length;
+
+		if( !(data = vips__file_read_name( 
+			import->input_profile_filename, 
+			vips__icc_dir(), &length )) )
+			return( -1 );
+
+		vips_image_set_blob( colour->out, VIPS_META_ICC_NAME, 
+			(VipsCallbackFn) vips_free, data, length );
+	}
+
 	return( 0 );
 }