fix vipsheader with new get/set system

TODO

@@ -1,3 +1,9 @@
+- look at vips_image_get_as_string() vs. vips_buf_appendgv()
+
+  should Hist and getext be true header fields?
+
+  vipsheader is not displaying filename correctly
+
 - not sure about utf8 error messages on win
 
 - strange: 

libvips/iofuncs/buf.c

@@ -493,19 +493,151 @@ vips_buf_appendd( VipsBuf *buf, int d )
  * @buf: the buffer
  * @value: #GValue to format and append
  *
- * Format and append a #GValue with g_strdup_value_contents().
+ * Format and append a #GValue. This doesn't use g_strdup_value_contents():
+ * that doesn't do what we want for some types and can change too much between
+ * glib versions.
  * 
  * Returns: %FALSE on overflow, %TRUE otherwise.
  */
 gboolean
 vips_buf_appendgv( VipsBuf *buf, GValue *value )
 {
-	char *str_value;
+	GType type = G_VALUE_TYPE( value ); 
+	GType fundamental = g_type_fundamental( type ); 
+
+	gboolean handled;
 	gboolean result;
 
-	str_value = g_strdup_value_contents( value );
-	result = vips_buf_appends( buf, str_value );
-	g_free( str_value );
+	result = FALSE;
+	handled = FALSE;
+
+	switch( fundamental ) {
+	case G_TYPE_STRING:
+		/* These are GStrings, vips refstrings are handled by boxed, see 
+		 * below.
+		 */
+		result = vips_buf_appends( buf, g_value_get_string( value ) ); 
+		handled = TRUE;
+		break;
+
+	case G_TYPE_OBJECT:
+{
+		GObject *object;
+
+		object = g_value_get_object( value );
+		if( VIPS_IS_OBJECT( object ) ) {
+			vips_object_summary( VIPS_OBJECT( object ), buf );
+			result = TRUE;
+			handled = TRUE;
+		}
+}
+		break;
+
+	case G_TYPE_INT:
+		result = vips_buf_appendf( buf, 
+			"%d", g_value_get_int( value ) );
+		handled = TRUE;
+		break;
+
+	case G_TYPE_UINT64:
+		result = vips_buf_appendf( buf, 
+			"%zd", g_value_get_uint64( value ) );
+		handled = TRUE;
+		break;
+
+	case G_TYPE_DOUBLE:
+		result = vips_buf_appendf( buf, 
+			"%g", g_value_get_double( value ) );
+		handled = TRUE;
+		break;
+
+	case G_TYPE_BOOLEAN:
+		result = vips_buf_appends( buf, 
+			g_value_get_boolean( value ) ? "true" : "false" );
+		handled = TRUE;
+		break;
+
+	case G_TYPE_ENUM:
+		result = vips_buf_appends( buf, 
+			vips_enum_nick( type, g_value_get_enum( value ) ) );
+		handled = TRUE;
+		break;
+
+	case G_TYPE_FLAGS:
+{
+		GFlagsClass *flags_class = g_type_class_ref( type );
+
+		GFlagsValue *v;
+		int flags;
+
+		flags = g_value_get_flags( value );
+
+		while( flags &&
+			(v = g_flags_get_first_value( flags_class, flags )) ) {
+			result = vips_buf_appendf( buf, "%s ", v->value_nick );
+			flags &= ~v->value;
+		}
+
+		handled = TRUE;
+}
+		break;
+
+	case G_TYPE_BOXED:
+		if( type == VIPS_TYPE_REF_STRING ||
+			type == VIPS_TYPE_BLOB ) {
+			const char *str;
+			size_t str_len;
+
+			str = vips_value_get_ref_string( value, &str_len );
+			result = vips_buf_appends( buf, str ); 
+			handled = TRUE;
+		}
+		else if( type == VIPS_TYPE_ARRAY_DOUBLE ) {
+			double *arr;
+			int n;
+			int i;
+
+			arr = vips_value_get_array_double( value, &n );
+			for( i = 0; i < n; i++ ) 
+				result = vips_buf_appendf( buf, "%g ", arr[i] ); 
+			handled = TRUE;
+		}
+		else if( type == VIPS_TYPE_ARRAY_INT ) {
+			int *arr;
+			int n;
+			int i;
+
+			arr = vips_value_get_array_int( value, &n );
+			for( i = 0; i < n; i++ ) 
+				result = vips_buf_appendf( buf, "%d ", arr[i] ); 
+			handled = TRUE;
+		}
+		else if( type == VIPS_TYPE_ARRAY_IMAGE ) {
+			VipsImage **arr;
+			int n;
+			int i;
+
+			arr = vips_value_get_array_image( value, &n );
+			for( i = 0; i < n; i++ ) {
+				vips_object_summary( VIPS_OBJECT( arr[i] ), 
+					buf );
+				result = vips_buf_appends( buf, " " ); 
+			}
+			handled = TRUE;
+		}
+		break;
+
+	default:
+		break;
+	}
+
+	if( !handled ) { 
+		char *str_value;
+
+		str_value = g_strdup_value_contents( value );
+		result = vips_buf_appends( buf, str_value );
+		g_free( str_value );
+	}
 
 	return( result );
 }

libvips/iofuncs/util.c

@@ -1806,6 +1806,7 @@ vips_flags_from_nick( const char *domain, GType type, const char *nick )
 	return( -1 );
 }
 
+
 /* Scan @buf for the first "%ns" (eg. "%12s") and substitute the 
  * lowest-numbered one for @sub. @buf is @len bytes in size.
  *

tools/vipsheader.c

@@ -106,33 +106,16 @@ static void *
 print_field_fn( VipsImage *image, const char *field, GValue *value, void *a )
 {
 	gboolean *many = (gboolean *) a;
-	const char *extra;
-	char *str_value;
-
-	/* Look for known enums and decode them.
-	 */
-	extra = NULL;
-	if( strcmp( field, "coding" ) == 0 )
-		extra = vips_enum_nick( 
-			VIPS_TYPE_CODING, g_value_get_int( value ) );
-	else if( strcmp( field, "format" ) == 0 )
-		extra = vips_enum_nick( 
-			VIPS_TYPE_BAND_FORMAT, g_value_get_int( value ) );
-	else if( strcmp( field, "interpretation" ) == 0 )
-		extra = vips_enum_nick( 
-			VIPS_TYPE_INTERPRETATION, g_value_get_int( value ) );
+	char str[256];
+	VipsBuf buf = VIPS_BUF_STATIC( str );
 
 	if( *many ) 
 		printf( "%s: ", image->filename );
 
-	str_value = g_strdup_value_contents( value );
-	printf( "%s: %s", field, str_value );
-	g_free( str_value );
+	printf( "%s: ", field ); 
 
-	if( extra )
-		printf( " - %s", extra );
-
-	printf( "\n" );
+	vips_buf_appendgv( &buf, value );
+	printf( "%s\n", vips_buf_all( &buf ) );
 
 	return( NULL );
 }
@@ -164,12 +147,14 @@ print_header( VipsImage *im, gboolean many )
 	else if( strcmp( main_option_field, "Hist" ) == 0 ) 
 		printf( "%s", vips_image_get_history( im ) );
 	else {
-		char *str;
+		GValue value = { 0 }; 
+		char str[256];
+		VipsBuf buf = VIPS_BUF_STATIC( str );
 
-		if( vips_image_get_as_string( im, main_option_field, &str ) )
-			return( -1 );
+		vips_image_get( im, main_option_field, &value );
+		vips_buf_appendgv( &buf, &value );
 		printf( "%s\n", str );
-		g_free( str );
+		g_value_unset( &value );
 	}
 
 	return( 0 );