much better handling of arrayimage cli args

we were not setting the access hint on arrayimage args, so

arrayjoin "$(echo *.jpg)" x.tif[bigtiff] --across 10

would open all the jpg images to memory, usually, in random mode

now arrayimage args see the operation's access hint (seq in this case),
for much better behaviour

also, we allow any whitespace as an arg separator in arrayimage from
string

ChangeLog

@@ -10,6 +10,7 @@
 - sharpen has a new @sigma param, @radius is deprecated
 - sharpen allows a much greater range of parameters
 - better handling of deprecated args in python
+- much better handling of arrayimage command-line args
 
 27/1/16 started 8.2.3
 - fix a crash with SPARC byte-order labq vips images

libvips/conversion/arrayjoin.c

@@ -134,6 +134,10 @@ vips_arrayjoin_build( VipsObject *object )
 		return( -1 );
 
 	in = vips_array_image_get( join->in, &n );
+	/* Array length zero means error.
+	 */
+	if( n == 0 )
+		return( -1 ); 
 
 	/* Move all input images to a common format and number of bands.
 	 */
@@ -291,6 +295,7 @@ vips_arrayjoin_class_init( VipsArrayjoinClass *class )
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *vobject_class = VIPS_OBJECT_CLASS( class );
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 
 	VIPS_DEBUG_MSG( "vips_arrayjoin_class_init\n" );
 
@@ -301,6 +306,8 @@ vips_arrayjoin_class_init( VipsArrayjoinClass *class )
 	vobject_class->description = _( "join an array of images" );
 	vobject_class->build = vips_arrayjoin_build;
 
+	operation_class->flags = VIPS_OPERATION_SEQUENTIAL_UNBUFFERED;
+
 	VIPS_ARG_BOXED( class, "in", -1, 
 		_( "Input" ), 
 		_( "Array of input images" ),

libvips/include/vips/image.h

@@ -493,6 +493,8 @@ int vips_system( const char *cmd_format, ... )
  */
 VipsArrayImage *vips_array_image_new( VipsImage **array, int n );
 VipsArrayImage *vips_array_image_newv( int n, ... );
+VipsArrayImage *vips_array_image_new_from_string( const char *string, 
+	VipsAccess flags );
 VipsArrayImage *vips_array_image_empty( void );
 VipsArrayImage *vips_array_image_append( VipsArrayImage *array, 
 	VipsImage *image );

libvips/iofuncs/object.c

@@ -1818,16 +1818,16 @@ vips_object_set_argument_from_string( VipsObject *object,
 		VipsOperationFlags flags;
 		VipsAccess access;
 
-		flags = 0;
-		if( VIPS_IS_OPERATION( object ) )
-			flags = vips_operation_get_flags( 
-				VIPS_OPERATION( object ) );
-
 		if( !value ) {
 			vips_object_no_value( object, name );
 			return( -1 );
 		}
 
+		flags = 0;
+		if( VIPS_IS_OPERATION( object ) )
+			flags = vips_operation_get_flags( 
+				VIPS_OPERATION( object ) );
+
 		/* Read the filename. 
 		 */
 		if( flags & VIPS_OPERATION_SEQUENTIAL_UNBUFFERED ) 
@@ -1850,6 +1850,44 @@ vips_object_set_argument_from_string( VipsObject *object,
 		 */
 		g_object_unref( out );
 	}
+	else if( g_type_is_a( otype, VIPS_TYPE_ARRAY_IMAGE ) ) { 
+		/* We have to have a special case for this, we can't just rely
+		 * on transform_g_string_array_image(), since we need to be
+		 * able to set the access hint on the image.
+		 */
+		VipsArrayImage *array_image;
+		VipsOperationFlags flags;
+		VipsAccess access;
+
+		if( !value ) {
+			vips_object_no_value( object, name );
+			return( -1 );
+		}
+
+		flags = 0;
+		if( VIPS_IS_OPERATION( object ) )
+			flags = vips_operation_get_flags( 
+				VIPS_OPERATION( object ) );
+
+		if( flags & VIPS_OPERATION_SEQUENTIAL_UNBUFFERED ) 
+			access = VIPS_ACCESS_SEQUENTIAL_UNBUFFERED;
+		else if( flags & VIPS_OPERATION_SEQUENTIAL ) 
+			access = VIPS_ACCESS_SEQUENTIAL;
+		else
+			access = VIPS_ACCESS_RANDOM; 
+
+		if( !(array_image = 
+			vips_array_image_new_from_string( value, access )) )
+			return( -1 ); 
+
+		g_value_init( &gvalue, VIPS_TYPE_ARRAY_IMAGE );
+		g_value_set_boxed( &gvalue, array_image );
+
+		/* Setting gvalue will have upped @array_image's count again,
+		 * go back to 1 so that gvalue has the only ref.
+		 */
+		vips_area_unref( (VipsArea *) array_image );
+	}
 	else if( g_type_is_a( otype, VIPS_TYPE_OBJECT ) &&
 		(oclass = g_type_class_ref( otype )) ) { 
 		VipsObject *new_object;

libvips/iofuncs/type.c

@@ -1089,43 +1089,6 @@ vips_array_double_get_type( void )
 	return( type );
 }
 
-static void
-transform_g_string_array_image( const GValue *src_value, GValue *dest_value )
-{
-	char *str;
-	int n;
-	char *p, *q;
-	int i;
-	VipsImage **array;
-
-	/* We need a copy of the string, since we insert \0 during
-	 * scan.
-	 */
-	str = g_value_dup_string( src_value );
-
-	n = 0;
-	for( p = str; (q = vips_break_token( p, " " )); p = q ) 
-		n += 1;
-
-	g_free( str );
-
-	vips_value_set_array_image( dest_value, n );
-	array = vips_value_get_array_image( dest_value, NULL );
-
-	str = g_value_dup_string( src_value );
-
-	for( i = 0, p = str; (q = vips_break_token( p, " " )); i++, p = q )
-		if( !(array[i] = vips_image_new_from_file( p, NULL )) ) {
-			/* Set the dest to length zero to indicate error.
-			 */
-			vips_value_set_array_image( dest_value, 0 );
-			g_free( str );
-			return;
-		}
-
-	g_free( str );
-}
-
 /**
  * vips_array_image_new:
  * @array: (array length=n): array of #VipsImage
@@ -1205,6 +1168,52 @@ vips_array_image_newv( int n, ... )
 	return( (VipsArrayImage *) area );
 }
 
+VipsArrayImage *
+vips_array_image_new_from_string( const char *string, VipsAccess access )
+{
+	char *str;
+	int n;
+	VipsArea *area;
+	VipsImage **array;
+	char *p, *q;
+	int i;
+
+	/* We need a copy of the string, since we insert \0 during
+	 * scan.
+	 */
+	str = g_strdup( string );
+
+	n = 0;
+	for( p = str; (q = vips_break_token( p, " \n\t\r" )); p = q ) 
+		n += 1;
+
+	g_free( str );
+
+	area = vips_area_new_array_object( n );
+	area->type = VIPS_TYPE_IMAGE;
+
+	array = vips_area_get_data( area, NULL, NULL, NULL, NULL );
+
+	str = g_strdup( string );
+
+	i = 0;
+	for( p = str; (q = vips_break_token( p, " \n\t\r" )); p = q ) {
+		if( !(array[i] = vips_image_new_from_file( p, 
+			"access", access,
+			NULL )) ) {
+			vips_area_unref( area ); 
+			g_free( str );
+			return( NULL );
+		}
+
+		i += 1;
+	}
+
+	g_free( str );
+
+	return( (VipsArrayImage *) area ); 
+}
+
 /**
  * vips_array_image_empty:
  *
@@ -1284,6 +1293,31 @@ vips_array_image_get( VipsArrayImage *array, int *n )
 	return( (VipsImage **) VIPS_ARRAY_ADDR( array, 0 ) ); 
 }
 
+static void
+transform_g_string_array_image( const GValue *src_value, GValue *dest_value )
+{
+	char *str;
+	VipsArrayImage *array_image; 
+
+	str = g_value_dup_string( src_value );
+
+	/* We can't get access here, just assume nothing. See the special case
+	 * in vips_object_new_from_string() for how we usually get this right.
+	 */
+	if( !(array_image = vips_array_image_new_from_string( str, 0 )) ) {
+		/* Set the dest to length zero to indicate error.
+		 */
+		vips_value_set_array_image( dest_value, 0 );
+		g_free( str );
+		return;
+	}
+
+	g_free( str );
+
+	g_value_set_boxed( dest_value, array_image );
+	vips_area_unref( (VipsArea *) array_image );
+}
+
 GType
 vips_array_image_get_type( void )
 {