Fix mag and attachment paths in Zarr annotation volume layer export (#1401)

* Update mag and attachment paths in volume layer export

* Update Changelog

Author: AndreaNathansen

webknossos/Changelog.md

@@ -19,6 +19,7 @@ For upgrade instructions, please check the respective _Breaking Changes_ section
 ### Changed
 
 ### Fixed
+- Fix mag and attachment paths in Zarr annotation volume layer export. [#1401](https://github.com/scalableminds/webknossos-libs/pull/1401)
 
 
 ## [3.0.4](https://github.com/scalableminds/webknossos-libs/releases/tag/v3.0.4) - 2025-11-26

webknossos/webknossos/annotation/volume_layer.py

@@ -21,8 +21,11 @@
 
 from webknossos.dataset_properties import (
     SEGMENTATION_CATEGORY,
+    AttachmentProperties,
     DataFormat,
     DatasetProperties,
+    MagViewProperties,
+    SegmentationLayerProperties,
     get_dataset_converter,
 )
 
@@ -283,10 +286,38 @@ def export_to_dataset(
                 assert len(datasource_properties.data_layers) == 1, (
                     f"Volume data zip must contain exactly one layer, got {len(datasource_properties.data_layers)}"
                 )
-                layer_properties = datasource_properties.data_layers[0]
+                layer_properties = cast(
+                    SegmentationLayerProperties, datasource_properties.data_layers[0]
+                )
                 internal_layer_name = layer_properties.name
                 layer_properties.name = layer_name
 
+                def replace_property_path(
+                    layer_property: AttachmentProperties | None,
+                ) -> None:
+                    if layer_property:
+                        layer_property.path = layer_property.path.replace(
+                            internal_layer_name, layer_name
+                        )
+
+                def replace_properties_path(
+                    properties: Sequence[AttachmentProperties | MagViewProperties]
+                    | None,
+                ) -> None:
+                    if properties:
+                        for layer_property in properties:
+                            if layer_property.path:
+                                layer_property.path = layer_property.path.replace(
+                                    internal_layer_name, layer_name
+                                )
+
+                replace_properties_path(layer_properties.mags)
+                replace_properties_path(layer_properties.attachments.meshes)
+                replace_properties_path(layer_properties.attachments.agglomerates)
+                replace_property_path(layer_properties.attachments.segment_index)
+                replace_property_path(layer_properties.attachments.cumsum)
+                replace_properties_path(layer_properties.attachments.connectomes)
+
                 _extract_zip_folder(
                     data_zip, dataset.path / layer_name, f"{internal_layer_name}/"
                 )