From 140a3b3ed07ced4ab70af9f02b3f9b6acc69410f Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Sat, 23 Dec 2017 14:53:15 +0000
Subject: [PATCH] try to improve error handling in magicksave

---
 libvips/foreign/magick.c     | 34 ++++++++++++++--------------------
 libvips/foreign/magick.h     |  4 ++--
 libvips/foreign/magicksave.c | 22 ++++++++++------------
 3 files changed, 26 insertions(+), 34 deletions(-)

diff --git a/libvips/foreign/magick.c b/libvips/foreign/magick.c
index 1a152d5e..61815944 100644
--- a/libvips/foreign/magick.c
+++ b/libvips/foreign/magick.c
@@ -96,26 +96,6 @@ magick_inherit_exception( ExceptionInfo *exception, Image *image )
 	(void) image;
 }
 
-static void *
-magick_genesis_cb( void *client )
-{
-#ifdef DEBUG
-	printf( "magick_genesis_cb:\n" ); 
-#endif /*DEBUG*/
-
-	MagickCoreGenesis( vips_get_argv0(), MagickFalse );
-
-	return( NULL );
-}
-
-void
-magick_genesis( void )
-{
-	static GOnce once = G_ONCE_INIT;
-
-	VIPS_ONCE( &once, magick_genesis_cb, NULL );
-}
-
 #endif /*HAVE_MAGICK7*/
 
 #ifdef HAVE_MAGICK
@@ -175,6 +155,20 @@ magick_inherit_exception( ExceptionInfo *exception, Image *image )
 	InheritException( exception, &image->exception );
 }
 
+#endif /*HAVE_MAGICK*/
+
+#if defined(HAVE_MAGICK) || defined(HAVE_MAGICK7)
+
+void
+magick_vips_error( const char *domain, ExceptionInfo *exception )
+{
+	if( exception &&
+		exception->reason &&
+		exception->description )
+		vips_error( domain, _( "libMagick error: %s %s" ),
+			exception->reason, exception->description );
+}
+
 static void *
 magick_genesis_cb( void *client )
 {
diff --git a/libvips/foreign/magick.h b/libvips/foreign/magick.h
index ef27a8db..c5aad7ab 100644
--- a/libvips/foreign/magick.h
+++ b/libvips/foreign/magick.h
@@ -53,9 +53,9 @@ int magick_import_pixels( Image *image, const ssize_t x, const ssize_t y,
 	const StorageType type,const void *pixels, ExceptionInfo *exception );
 void magick_set_property( Image *image, const char *property, const char *value,
 	ExceptionInfo *exception );
-int magick_set_image_colorspace( Image *image, const ColorspaceType colorspace,
-	ExceptionInfo *exception );
+
 void magick_inherit_exception( ExceptionInfo *exception, Image *image );
+void magick_vips_error( const char *domain, ExceptionInfo *exception );
 
 void magick_genesis( void );
 
diff --git a/libvips/foreign/magicksave.c b/libvips/foreign/magicksave.c
index 2bd58763..fed63226 100644
--- a/libvips/foreign/magicksave.c
+++ b/libvips/foreign/magicksave.c
@@ -201,6 +201,7 @@ vips_foreign_save_magick_create( VipsForeignSaveMagick *magick, VipsImage *im )
 static int
 vips_foreign_save_magick_build( VipsObject *object )
 {
+	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( object ); 
 	VipsForeignSave *save = (VipsForeignSave *) object;
 	VipsForeignSaveMagick *magick = (VipsForeignSaveMagick *) object;
 
@@ -246,6 +247,8 @@ vips_foreign_save_magick_build( VipsObject *object )
 		break;
 
 	default:
+		vips_error( class->nickname, 
+			"%s", _( "unsupported image format" ) );
 		return( -1 );
 	}
 
@@ -275,6 +278,8 @@ vips_foreign_save_magick_build( VipsObject *object )
 		break;
 
 	default:
+		vips_error( class->nickname, 
+			"%s", _( "unsupported number of image bands" ) );
 		return( -1 );
 	}
 
@@ -294,8 +299,10 @@ vips_foreign_save_magick_build( VipsObject *object )
 	if( magick->quality > 0 ) 
 		magick->image_info->quality = magick->quality;
 
-	if( vips_foreign_save_magick_create( magick, im ) )
+	if( vips_foreign_save_magick_create( magick, im ) ) {
+		magick_vips_error( class->nickname, magick->exception ); 
 		return( -1 ); 
+	}
 
 	return( 0 );
 }
@@ -385,12 +392,7 @@ vips_foreign_save_magick_file_build( VipsObject *object )
 	if( !WriteImages( magick->image_info, magick->images,
 		magick->image_info->filename, magick->exception ) ) {
 		magick_inherit_exception( magick->exception, magick->images );
-		vips_error( class->nickname, 
-			_( "unable to write file \"%s\"\n" 
-				"libMagick error: %s %s" ),
-			file->filename,
-			magick->exception->reason, 
-			magick->exception->description );
+		magick_vips_error( class->nickname, magick->exception );
 
 		return( -1 );
 	}
@@ -459,11 +461,7 @@ vips_foreign_save_magick_buffer_build( VipsObject *object )
 	if( !(obuf = ImagesToBlob( magick->image_info, magick->images, 
 		&olen, magick->exception )) ) { 
 		magick_inherit_exception( magick->exception, magick->images );
-		vips_error( class->nickname, 
-			_( "unable to write buffer\n"
-				"libMagick error: %s %s" ),
-			magick->exception->reason, 
-			magick->exception->description );
+		magick_vips_error( class->nickname, magick->exception );
 
 		return( -1 );
 	}