From ac3ce8b01051e0b7ad1c60df7589b0027befcfc6 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Sun, 28 Aug 2011 12:46:50 +0100
Subject: [PATCH] add VIPS_ARGUMENT_APPEND

to give more control over arg ordering, fixes a problem in avg
---
 ChangeLog                     | 1 +
 TODO                          | 5 +++--
 libvips/arithmetic/avg.c      | 2 +-
 libvips/include/vips/object.h | 4 +++-
 libvips/iofuncs/enumtypes.c   | 1 +
 libvips/iofuncs/object.c      | 8 ++++++--
 libvips/iofuncs/operation.c   | 6 +++++-
 7 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 6080aeea..1d07792f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,7 @@
 20/8/11 started 7.27.0
 - version bump for new dev cycle
 - im_subtract(), im_avg() redone as classes
+- added VIPS_ARGUMENT_APPEND to help control arg ordering
 
 10/8/11 started 7.26.3
 - don't use G_VALUE_COLLECT_INIT(), many platforms do not have a glib this
diff --git a/TODO b/TODO
index 34e36cd4..f1370662 100644
--- a/TODO
+++ b/TODO
@@ -1,9 +1,10 @@
 - oops
 
-	$ vips im_avg babe.jpg
+	$ vips avg 
 	Segmentation fault
 
-  test 7.26 as well, argh
+  because we don't test that all args have been set until the end of build,
+  and statistic_build assumes that in has been set
 
 
 
diff --git a/libvips/arithmetic/avg.c b/libvips/arithmetic/avg.c
index 895e9d60..97642f07 100644
--- a/libvips/arithmetic/avg.c
+++ b/libvips/arithmetic/avg.c
@@ -256,7 +256,7 @@ vips_avg_class_init( VipsAvgClass *class )
 	g_object_class_install_property( gobject_class, 
 		PROP_OUTPUT, pspec );
 	vips_object_class_install_argument( object_class, pspec,
-		VIPS_ARGUMENT_REQUIRED_OUTPUT, 
+		VIPS_ARGUMENT_REQUIRED_OUTPUT | VIPS_ARGUMENT_APPEND, 
 		G_STRUCT_OFFSET( VipsAvg, avg ) );
 }
 
diff --git a/libvips/include/vips/object.h b/libvips/include/vips/object.h
index 8f7af978..c5c2df87 100644
--- a/libvips/include/vips/object.h
+++ b/libvips/include/vips/object.h
@@ -52,6 +52,7 @@ typedef struct _VipsObjectClass VipsObjectClass;
  * @VIPS_ARGUMENT_SET_ONCE: can only be set once
  * @VIPS_ARGUMENT_INPUT: is an input argument (one we depend on)
  * @VIPS_ARGUMENT_OUTPUT: is an output argument (depends on us)
+ * @VIPS_ARGUMENT_APPEND: add to end of arg list (default is prepend)
  *
  * Flags we associate with each object argument.
  *
@@ -66,7 +67,8 @@ typedef enum {
 	VIPS_ARGUMENT_CONSTRUCT = 2,
 	VIPS_ARGUMENT_SET_ONCE = 4,
 	VIPS_ARGUMENT_INPUT = 8,
-	VIPS_ARGUMENT_OUTPUT = 16
+	VIPS_ARGUMENT_OUTPUT = 16,
+	VIPS_ARGUMENT_APPEND = 32
 } VipsArgumentFlags;
 
 /* Useful flag combinations. User-visible ones are:
diff --git a/libvips/iofuncs/enumtypes.c b/libvips/iofuncs/enumtypes.c
index 7a311e7a..c87c2e9f 100644
--- a/libvips/iofuncs/enumtypes.c
+++ b/libvips/iofuncs/enumtypes.c
@@ -158,6 +158,7 @@ vips_argument_flags_get_type( void )
 			{VIPS_ARGUMENT_SET_ONCE, "VIPS_ARGUMENT_SET_ONCE", "set-once"},
 			{VIPS_ARGUMENT_INPUT, "VIPS_ARGUMENT_INPUT", "input"},
 			{VIPS_ARGUMENT_OUTPUT, "VIPS_ARGUMENT_OUTPUT", "output"},
+			{VIPS_ARGUMENT_APPEND, "VIPS_ARGUMENT_APPEND", "append"},
 			{0, NULL, NULL}
 		};
 		
diff --git a/libvips/iofuncs/object.c b/libvips/iofuncs/object.c
index 6a86998d..d0605b63 100644
--- a/libvips/iofuncs/object.c
+++ b/libvips/iofuncs/object.c
@@ -1119,8 +1119,12 @@ vips_object_class_install_argument( VipsObjectClass *object_class,
 
 	vips_argument_table_replace( object_class->argument_table,
 		(VipsArgument *) argument_class );
-	object_class->argument_table_traverse = g_slist_prepend(
-		object_class->argument_table_traverse, argument_class );
+	if( flags & VIPS_ARGUMENT_APPEND )
+		object_class->argument_table_traverse = g_slist_append(
+			object_class->argument_table_traverse, argument_class );
+	else
+		object_class->argument_table_traverse = g_slist_prepend(
+			object_class->argument_table_traverse, argument_class );
 }
 
 /* Set a named arg from a string.
diff --git a/libvips/iofuncs/operation.c b/libvips/iofuncs/operation.c
index ff63c076..cf96d009 100644
--- a/libvips/iofuncs/operation.c
+++ b/libvips/iofuncs/operation.c
@@ -28,8 +28,8 @@
  */
 
 /*
-#define VIPS_DEBUG
  */
+#define VIPS_DEBUG
 
 #ifdef HAVE_CONFIG_H
 #include <config.h>
@@ -718,8 +718,12 @@ vips_call_argv( VipsOperation *operation, int argc, char **argv )
 	printf( "vips_call_argv: " );
 	vips_object_print_name( VIPS_OBJECT( operation ) );
 	printf( "\n" );
+{
+	int i;
+
 	for( i = 0; i < argc; i++ )
 		printf( "%d) %s\n", i, argv[i] );
+}
 #endif /*VIPS_DEBUG*/
 
 	call.operation = operation;